Keyword Reference - By usage

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Arrays and Data Storage

Arrays

• _DEFINE (statement) defines a range of untyped variable names according to their first character as a datatype.
• _PRESERVE (REDIM option) preserves the existing element values when an array is resized.
• CLEAR (statement) resets all variable values and array element values to 0 or null strings and closes all open files.
• DIM (statement) dimensions(sizes) a static array and defines the type.
• $DYNAMIC (metacommand) defines that all arrays are dynamic or changeable in size.
• ERASE (array statement) clears a static array of all values and totally removes a dynamic array.
• LBOUND (array function) returns the lowest valid index (lower boundary) of an array.
• OPTION BASE (statement) sets the default starting index of an array to 0 or 1.
• REDIM (statement) re-dimensions the number of elements in a dynamic(resizeable) array and defines the type.
• SHARED (statement) designates variable values that can be shared with sub-procedures without using parameters.
• STATIC (statement) defines a variable or list of variables that will retain their values after the sub-procedure is exited.
• $STATIC (metacommand) defines that all arrays are static or unchangeable in size.
• SWAP (statement) trades the values of two numerical or string values or array elements.
• UBOUND (array function) returns the highest valid index (upper boundary) of an array.

See also: Arrays

Fixed Program DATA

• DATA (statement) creates a field of built-in program data values separated by commas.
• READ (statement) reads the DATA from the data field sequentially.
• RESTORE (statement) sets the data pointer to the start of all DATA or a specified DATA field.

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Colors and Transparency

• _ALPHA (function) returns the alpha channel transparency level of a color value used on a screen page or image.
• _ALPHA32 (function) function returns the alpha channel level of a 32 bit color value only.
• _BACKGROUNDCOLOR (function) returns the current background color for an image handle or page.
• _BLEND (statement) turns on alpha blending for the current image or a specific one.
• _BLEND (function) returns if blending is enabled or disabled for the current window or a specified image handle.
• _BLINK (statement) statement turns blinking colors on/off in SCREEN 0
• _BLINK (function) returns -1 if enabled or 0 if disabled by _BLINK statement.
• _BLUE (function) returns the palette intensity OR the blue component intensity of a 32-bit image color.
• _BLUE32 (function) returns the blue component intensity of a 32-bit image color.
• _CLEARCOLOR (statement) sets a specific color to be treated as transparent in an image
• _CLEARCOLOR (function) returns the current transparent color of an image.
• _COLORCHOOSERDIALOG (function) Displays a standard color picker dialog box and returns a 32-bit RGBA color selected by the user.
• _COPYPALETTE (statement) copies the color palette intensities from one image to another image or screen page.
• _DEFAULTCOLOR (function) returns the current default (text/drawing) color for an image handle or page.
• _DONTBLEND (statement) turns off alpha blending for an image handle.
• _GREEN (function) returns the palette index OR the green component intensity of a 32-bit image.
• _GREEN32 (function) returns the green component intensity of a 32-bit image color.
• _NEWIMAGE (function) prepares a custom sized program SCREEN or page surface that can use 256 or 32 bit colors.
• _PALETTECOLOR (statement) sets the color value of a palette entry of an image using 256 color modes or less (4 or 8 BPP).
• _PALETTECOLOR (function) returns the 32 bit attribute color setting of an image or screen page handle's palette.
• _PIXELSIZE (function) returns the color depth (Bits Per Pixel) of an image.
• _RED (function) returns the palette index OR the red component intensity of a 32-bit screen.
• _RED32 (function) returns the red component intensity of a 32-bit image color.
• _RGB (function) returns the closest palette attribute index OR the LONG 32 bit color value in 32 bit screens.
• _RGB32 (function) returns the LONG 32 bit color value only.
• _RGBA (function) returns the closest palette attribute index OR the LONG 32 bit color value in _ALPHA screens.
• _RGBA32 (function) returns the LONG 32 bit _ALPHA color value only.
• _SETALPHA (statement) sets the alpha channel transparency level of some or all of the pixel colors of an image.

• CLS (statement) clears the screen and can set the background color in QB64.
• COLOR (statement) sets the current text color attribute or _RGB value to be used or background colors in some screen modes.
• INP (function) returns the RGB color intensity values from color port register &H3C9 for a specific attributes.
• OUT (statement) sets the color port access mode and sets the RGB color intensity values using &H3C9.
• PALETTE (statement) sets the Red, Green and Blue color attribute intensities using a RGB multiplier calculation.
• PALETTE USING (statement) sets the color intensity settings using a designated array.
• POINT (function) returns a pixel coordinate color attribute or the LONG _RGB color value of a 32 bit color.
• PRESET (statement) sets a pixel coordinate to the background color or a color specified.
• PSET (statement) sets a pixel coordinate a specified color or uses the current color when not designated.
• SCREEN sets the screen mode of a program which may determine the number of colors available in legacy modes.

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Console Window

• $CONSOLE (QB64 Metacommand) creates a console window throughout the program.
• _CONSOLE (statement) can be used to turn the console window OFF or ON or designate it as _DEST _CONSOLE for output.
• _CONSOLETITLE (statement) creates a title for the console window using a literal or variable string.
• $SCREENHIDE (QB64 Metacommand) hides the program window throughout the program until $SCREENSHOW is used.
• _SCREENHIDE hides the main program window in a section of code until _SCREENSHOW is used.
• $SCREENSHOW (QB64 Metacommand) displays the main program window throughout the program after $SCREENHIDE has been used.
• _SCREENSHOW displays the main program window in a section of code after _SCREENHIDE has been used.
• SHELL (QB64 function) executes a DOS command or calls another program. Returns codes sent by END or SYSTEM.
• _SHELLHIDE (function) hides a DOS command or call to another program. Returns codes sent by END or SYSTEM.

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Conditional Operations

• AND (boolean) returns True if all of the arguments are True.
• NOT (boolean) returns the opposite condition of an argument.
• OR (boolean) returns True if one of the arguments is True.
• XOR (boolean) returns True if only one of two arguments are True.

See also: Logical Operations and Relational Operations

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Definitions and Variable Types

• _BIT {` numerical type) values of 0 (bit off) or -1 (bit on). Unsigned of 0 or 1.
• _BYTE {%% numerical type) values from -128 to 127 (one byte or 8 _BITs). Unsigned from 0 to 255.
• _DEFINE (statement) defines a range of untyped variable names according to their first character as a datatype.
• _FLOAT {## numerical type) values offer the maximum floating-point decimal precision available using QB64.
• _INTEGER64 (&& numerical type) values -9223372036854775808 to 9223372036854775807. Unsigned to 18446744073709551615.
• _MEM (variable type) contains read only dot elements for the OFFSET, SIZE, TYPE and ELEMENTSIZE of a block of memory.
• _OFFSET(%& variable type) can store any memory offset integer value when using DECLARE LIBRARY or _MEMory only.
• _UNSIGNED {~ numerical type) defines an integer numerical value as being positive only in QB64.
• COMMON (statement) shares common variable values with other Linked or CHAINed programs.
• COMMON SHARED (statement) shares common variable values with all sub-procedures and other Linked or CHAINed programs.
• CONST (statement) defines one or more named numeric or string shared values which can not change in a program.
• DEFDBL (statement) defines undefined variable starting letters AS DOUBLE variables instead of the SINGLE type default.
• DEFINT (statement) defines undefined variable starting letters AS INTEGER variables instead of the SINGLE type default.
• DEFLNG (statement) defines undefined variable starting letters AS LONG variables instead of the SINGLE type default.}}
• DEFSNG (statement) defines undefined variable starting letters AS SINGLE variables instead of the SINGLE type default.
• DEFSTR (statement) defines undefined variable starting letters AS STRING variables instead of the SINGLE type default.
• DIM defines a variable or size a static array and can define the type of value it returns.
• DOUBLE {# numerical type) an 8 byte floating decimal variable type with numerical values up to 15 decimal places.
• INTEGER {% numerical type) a two byte variable type with values from -32768 to 32767. Unsigned to 65535.
• LONG {& numerical type) Integer values can be from -2147483648 to 2147483647. _UNSIGNED values to 4294967295.
• OPTION BASE (statement) sets the default starting index of an array to 0 or 1.
• REDIM defines and sizes a dynamic(changeable) array and can define the type of value returned.
• SHARED (statement) designates variable values that can be shared with sub-procedures without using SUB parameters.
• SINGLE (! numerical type) a 4 byte floating decimal variable type with numerical values up to 7 decimal places.
• STATIC (statement) defines a variable or list of variables that will retain their values after the sub-procedure is exited.
• STRING ($ variable type) one byte text variable with ASCII code values from 0 to 255.
• TYPE (statement) defines variable types that can hold more than one variable type value of a fixed byte length.

See also: QB64 Variable Types and C++ Variable Types

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External Disk and API calls

• _ACCEPTFILEDROP (statement) turns a program window into a valid drop destination for dragging files from Windows Explorer.
• _DEVICE$ (function) returns a STRING expression listing device names and input types of system input devices.
• _DEVICES (function) returns the number of input devices found on a computer system.
• _DIREXISTS (function) returns -1 if the directory folder name string parameter exists. Zero if it does not.
• _DROPPEDFILE (function) returns the list of items (files or folders) dropped in a program's window after _ACCEPTFILEDROP is enabled.
• _CLIPBOARD$ (statement) sends STRING data to the Clipboard.
• _CLIPBOARD$ (function) returns the current contents of the Clipboard as a string.
• _CLIPBOARDIMAGE (function) pastes an image from the clipboard into a new QB64 image in memory.
• _CLIPBOARDIMAGE (statement) copies a valid QB64 image to the clipboard.
• _CWD$ (function) returns the current working directory path as a STRING.
• _DONTWAIT (SHELL action) allows the program to continue without waiting for the other program to close.
• _FILEEXISTS (function) returns -1 if the file name string parameter exists. Zero if it does not.
• _FINISHDROP (statement) resets _TOTALDROPPEDFILES and clears the _DROPPEDFILE list of items (files/folders).
• _HIDE (SHELL action) hides the DOS screen output during a shell.
• _LASTBUTTON (function) returns the number of buttons available on a specified number device listed by DEVICE$.
• _OPENFILEDIALOG$ (function) Displays a standard dialog box that prompts the user to open a file.
• _OS$ (function) returns the QB64 compiler version in which the program was compiled as [WINDOWS], [LINUX] or [MACOSX] and [32BIT] or [64BIT].
• _SAVEFILEDIALOG$ (function) Displays a standard dialog box that prompts the user to save a file.
• _SCREENCLICK simulates clicking the mouse at a position on the screen to get focus.
• _SCREENIMAGE captures the current desktop screen image.
• _SCREENPRINT simulates keyboard entries on the desktop.
• _SELECTFOLDERDIALOG$ (function) Displays a dialog box that enables the user to select a folder (directory).
• _SHELLHIDE (function) executes a DOS command or calls another program. Returns codes sent by END or SYSTEM.
• _STARTDIR$ (function) returns the user's program calling path as a STRING.
• _TOTALDROPPEDFILES (function) returns the number of items (files or folders) dropped in a program's window after _ACCEPTFILEDROP is enabled.

• CHDIR (statement) changes the program path to a new path.
• COMMAND$ (function) returns command line parameters sent when a program is started.
• ENVIRON (statement) temporarily sets an environmental key/pair value.
• ENVIRON$ (function) returns the environmental settings of the computer.
• _ENVIRONCOUNT (function) returns the number of key/value pairs currently exist in the environment table.
• FILES (statement) displays a specified list of files.
• MKDIR (statement) creates a new directory folder in the designated path.
• NAME (statement) renames a file.
• RMDIR (statement) removes an empty directory folder from the specified path.
• SHELL (statement) performs a command line operation in DOS.
• SHELL (QB64 function) executes a DOS command or calls another program. Returns codes sent by END or SYSTEM.

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Error Trapping

• _ASSERT (statement) Performs debug tests.
• $ASSERTS (metacommand) Enables the _ASSERT macro* $CHECKING (Metacommand) turns off or on error event checking and strips error code from compiled programs.
• _ERRORLINE (function) returns the actual text code line where a program error occurred.
• ERR (function) returns the error code number of the last error to occur.
• ERROR (statement) simulates a program error based on the error code number used.
• ERL (function) returns the closest line number before an error occurred if the program uses them.
• ON ERROR (statement) GOTO sends the program to a line number or label when an error occurs. Use to avoid program errors.
• RESUME (statement) error statement sends the program to the NEXT code line or a designated line number or label .

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Event Trapping

• _AUTODISPLAY (statement) enables the automatic display of the screen image changes previously disabled by _DISPLAY.
• _DELAY (statement) suspends program execution for a SINGLE value of seconds down to milliseconds.
• _DISPLAY (statement) turns off automatic display while only displaying the screen changes when called.
• _EXIT (function) prevents a user exit and indicates if a user has clicked the close X window button or CTRL + BREAK.
• _FREETIMER (function) returns a free TIMER number for multiple ON TIMER(n) events.
• _MOUSEINPUT (function) reports any changes to the mouse status and MUST be used to read those changes.
• _SHELLHIDE (function) returns the code sent by a program exit using END or SYSTEM followed by an INTEGER value.

• OFF turns event checking off and does not remember subsequent events.
• ON turns event checking on.
• ON ERROR GOTO (event statement) executes when a program error occurs
• ON KEY(n) (event statement) executes when a keypress or keypress combination occurs.
• ON TIMER(n) (event statement) executes when a timed event occurs. QB64 can use multiple numbered timers.
• ON...GOSUB (event statement) branches to a line number or label according to a numerical ordered list of labels.
• ON...GOTO (event statement) branches to a line number or label according to a numerical ordered list of labels.
• STOP suspends event checking and remembers subsequent events that are executed when events are turned back on.
• TIMER (function) returns the number of seconds past the previous midnite down to a QB64 accuracy of one millisecond.
• TIMER (statement) enables, turns off or stops timer event trapping. In QB64 TIMER(n) FREE can free multiple timers.
• WAIT (statement) normally used to delay program display execution during or after vertical retrace periods.

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File Input and Output

• _DIREXISTS (function) returns -1 if the directory folder name string parameter exists. Zero if it does not.
• _FILEEXISTS (function) returns -1 if the file name string parameter exists. Zero if it does not.
• ACCESS (clause) used in a networking OPEN statement to allow READ or WRITE access to files.
• APPEND (file mode) opens or creates a file that can be appended with data at the end.
• BINARY (file mode) opens or creates a file that can be byte accessed using both GET and PUT.
• BLOAD (statement) opens a binary file and loads the contents to a specific array.
• BSAVE (statement) creates a binary file that holds the contents of a specified array.
• CHDIR (statement) changes the program path to a new path.
• CLOSE (statement) closes a specified file or all open files.
• EOF (file function) returns -1 when the end of a file has been read.
• FIELD (statement) creates a STRING type definition for a random-access file buffer.
• FILES (statement) displays a specified list of files.
• FREEFILE (file function) returns a file access number that is currently not in use.
• GET (file I/O statement) reads file data by byte or record positions.
• INPUT (file mode) only OPENs existing sequential files for program INPUT.
• INPUT (file statement) reads sequential file data that was created using PRINT # or WRITE #.
• INPUT$ (function) reads a specific number of bytes from random or binary files.
• KILL (statement) deletes a specified file without asking for verification. Remove empty folders with RMDIR.
• LINE INPUT (file statement) reads an entire text row of printed sequential file data.
• LOC (function) finds the current file location or size of a COM port receive buffer.
• LOCK (statement) prevents access to a file.
• LOF (file function) returns the size of a file in bytes.
• MKDIR (statement) creates a new folder in the designated path.
• NAME (statement) renames a file AS a new file name.
• OPEN (file I/O statement) opens a specified file FOR an access mode with a set reference number.
• OUTPUT (file mode) opens or creates a new file that holds no data.
• PRINT (file statement) writes text and numerical data into a file.
• PRINT USING (file statement) writes template formatted text into a file.
• PUT (file I/O statement) writes data into a RANDOM or BINARY file by byte or record position.
• RANDOM (file mode) opens or creates a file that can be accessed using both GET and PUT.
• RESET (statement) closes all files and writes the directory information to a diskette.
• RMDIR (statement) removes an empty folder from the specified path.
• SEEK (function) returns the current read or write byte position in a file.
• SEEK (statement) sets the current read or write byte position in a file.
• UNLOCK (statement) unlocks access to a file.
• WIDTH (statement) sets the text width of a file.
• WRITE (file statement) writes numerical and string data to a sequential file using comma separators.

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Fonts

• _FONT (function) creates a new alphablended font handle from a designated image handle
• _FONT (statement) sets the current _LOADFONT function font handle to be used by PRINT or _PRINTSTRING.
• _FONTHEIGHT (function) returns the font height of a font handle created by _LOADFONT.
• _FONTWIDTH (function) returns the font width of a MONOSPACE font handle created by _LOADFONT.
• _FREEFONT (statement) frees a font handle value from memory
• _LOADFONT (function) loads a TrueType font (.TTF) file of a specific size and style and returns a font handle value.
• _MAPUNICODE (statement) maps a Unicode value to an ASCII character code value.
• _PRINTMODE (function) returns the present _PRINTMODE status as a numerical value.
• _PRINTMODE (statement) sets the text or _FONT printing mode on a background image when using PRINT or _PRINTSTRING.

• _KEEPBACKGROUND (1): Text background transparent. Only the text is displayed over anything behind it.
• _ONLYBACKGROUND (2): Text background is only displayed. Text is transparent to anything behind it.
• _FILLBACKGROUND (3): Text and background block anything behind them like a normal PRINT. Default setting.

• _PRINTSTRING (statement) prints text or custom font strings using graphic column and row coordinate positions.
• _PRINTWIDTH (function) returns the width in pixels of the _FONT or text string that a program will print.
• PRINT (statement) prints numeric or string expressions to the program screen.
• PRINT USING (statement) prints template formatted numeric or string values to the program screen.
• WRITE (screen I/O statement) writes a comma-separated list of values to the screen.

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Game Controller Input (Joystick)

• _AXIS (function) returns a SINGLE value between -1 and 1 indicating the maximum distance from device axis center 0.
• _BUTTON (function) returns -1 when a device button is pressed and 0 when button is released.
• _BUTTONCHANGE (function) returns -1 when a device button has been pressed and 1 when released. Zero indicates no change.
• _DEVICE$ (function) returns a STRING expression listing a designated numbered input device name and types of input.
• _DEVICEINPUT (function) returns the _DEVICES number of an _AXIS, _BUTTON or _WHEEL event.
• _DEVICES (function) returns the number of input devices found on a computer system including the keyboard and mouse.
• _LASTAXIS (function) returns the number of axis available on a specified number device listed by _DEVICE$.
• _LASTBUTTON (function) returns the number of buttons available on a specified number device listed by DEVICE$.
• _LASTWHEEL (function) returns the number of scroll wheels available on a specified number device listed by _DEVICE$.
• _MOUSEMOVEMENTX (function) returns the relative horizontal position of the mouse cursor compared to the previous position.
• _MOUSEMOVEMENTY (function) returns the relative vertical position of the mouse cursor compared to the previous position.
• _WHEEL (function) returns -1 when a device wheel is scrolled up and 1 when scrolled down. Zero indicates no activity.
• ON STRIG(n) (event statement) directs program flow upon a button press event of a game controller device.
• STICK (function) returns the directional axis coordinate values from 1 to 254 of game port (&H201) or USB controller devices.
• STRIG (function) returns the True or False button press status of game port (&H201) or USB controller devices.
• STRIG(n) (statement) enables, suspends or disables event trapping of STRIG button return values.

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Graphic Commands

• _COPYIMAGE (function) can copy a software surface to a hardware accelerated surface handle using mode 33.
• _DISPLAY (statement) renders surfaces visible in the _DISPLAYORDER previously set in the QB64 program.
• _DISPLAYORDER sets the rendering order of _SOFTWARE, _HARDWARE and _GLRENDER with _DISPLAY.
• _LOADIMAGE (function) can load images as hardware accelerated using mode 33.
• _MOUSESHOW (statement) a special string parameter after command in GL allows some special cursor shapes.
• _PUTIMAGE (statement) can place GL surfaces and allows the _SMOOTH action to blend stretched surfaces.

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Graphics and Imaging:

• _AUTODISPLAY (statement) enables the automatic display of the screen image changes previously disabled by _DISPLAY.
• _CLIP (PUT action) allows placement of an image partially off of the screen.
• _COPYIMAGE (function) function duplicates an image handle from a designated handle.
• _COPYPALETTE (statement) copies the color palette intensities from one image to another image or screen page.
• _DESKTOPHEIGHT (function) returns the height of the desktop (not program window).
• _DESKTOPWIDTH (function) returns the width of the desktop (not program window).
• _DEST (statement) sets the current write image or page. All graphics will go to this image.
• _DEST (function) returns the current write destination image or page.
• _DISPLAY (statement) turns off automatic display while only displaying the screen changes when called.
• _DISPLAY (function) returns the handle of the current image that is displayed on the screen.
• _FULLSCREEN (function) returns the present full screen mode setting of the screen window.
• _FULLSCREEN (statement) sets the full screen mode of the screen window. Alt + Enter can do it manually.
• _FREEIMAGE (statement) releases an image handle value from memory when no longer needed.
• _HEIGHT (function) returns the height of an image handle or current write page.
• _ICON (function) places an image in the title bar using a _LOADIMAGE handle.
• _LOADIMAGE (function) loads a graphic file image into memory and returns an image handle.
• _MAPTRIANGLE (statement) maps a triangular portion of an image to a destination image or screen page.
• _NEWIMAGE (function) prepares a window image or page surface and returns the handle value.
• _PIXELSIZE (function) returns the color depth (Bits Per Pixel) of an image.
• _PRINTSTRING (statement) prints text or custom font strings using graphic column and row coordinate positions.
• _PUTIMAGE (statement) maps a rectangular area of a source image to an area of a destination image in one operation
• _SCREENIMAGE (function) creates an image of the current desktop and returns an image handle.
• _SMOOTH (function) checks whether the current _FULLSCREEN mode has antialiasing enabled or not.
• _SOURCE (statement) establishes the image SOURCE using a designated image handle
• _SOURCE (function) returns the present image _SOURCE handle value.
• _WIDTH (function) returns the width of an image handle or current write page.

• CIRCLE (statement) is used in graphics SCREEN modes to create circles, arcs or ellipses.
• CLS (statement) clears a screen page or the program SCREEN. QB64 can clear with a color.
• COLOR (statement) sets the current text color attribute or _RGB value to be used or background colors in some screen modes.
• DRAW (statement) uses a special type of string expression to draw lines on the screen.
• GET (graphics statement) used to store a box area image of the screen into an INTEGER array.
• LINE (statement) used in graphic SCREEN modes to create lines or boxes.
• PAINT (statement) used to color enclosed graphic objects with a designated fill color and border color.
• PALETTE (statement) can swap color settings, set colors to default or set the Red, Green, Blue color palette.
• PALETTE USING (statement) sets all RGB screen color intensities using values from an array.
• PCOPY (statement) copies one source screen page to a destination page in memory.
• PMAP (function) returns the physical or WINDOW view coordinates.
• POINT (function) returns the pixel COLOR attribute or _RGB value at a specified graphics coordinate.
• PRESET (statement) sets a pixel coordinate to the background color or a designated color.
• PSET (statement) sets a pixel coordinate to the default color or designated color attribute.
• PUT (graphics statement) statement is used to place GET saved or BSAVEd images stored in an array.
• SCREEN sets the screen mode of a program. No statement defaults the program to SCREEN 0 text only mode.
• STEP (relational statement) is used to step through FOR loop values or use relative graphical coordinates.
• VIEW (graphics statement) creates a graphics view port area by defining the coordinate limits to be viewed.
• WINDOW (statement) defines the coordinate dimensions of the current graphics viewport.

See also: Bitmaps, Icons and Cursors, SAVEIMAGE, GIF Images

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Keyboard Input

• _CONTROLCHR (statement) OFF allows the control characters to be used as text characters. ON(default) can use them as commands.
• _CONTROLCHR (function) returns the current state of _CONTROLCHR as 1 when OFF and 0 when ON.
• _EXIT (function) prevents a program user exit and indicates if a user has clicked the close X window button or CTRL + BREAK.
• _INPUTBOX$ (function) Displays a prompt in a dialog box, waits for the user to input text or click a button, and returns a string containing the contents of the text box.
• _KEYDOWN (function) returns whether modifying keys like CTRL, ALT, SHIFT, and any other keys are pressed.
• _KEYHIT (function) returns ASCII one and two byte, SDL Virtual Key and Unicode keyboard key press codes.
• _SCREENPRINT (statement) simulates typing text into another OS program using the keyboard.

• INKEY$ (function) returns the ASCII string character of a keypress.
• INPUT (statement) requests a STRING or numerical keyboard entry from a program user.
• INPUT$ (function) used to get a set number of keypress characters or bytes from a file.
• INP (function) returns a scan code value from keyboard register &H60(96) to determine key presses.
• KEY n (event statement) is used to assign a "softkey" string to a key and/or display them.
• KEY(n) (event statement) assigns, enables, disables or suspends event trapping of a keypress.
• KEY LIST (statement) lists the 12 Function key soft key string assignments going down left side of screen.
• LINE INPUT (statement) requests a STRING keyboard entry from a program user.
• ON KEY(n) (event statement) defines a line number or label to go to when a specified key is pressed.
• SLEEP (statement) pauses the program for a specified number of seconds or a until a key press.

See also: Keyboard scancodes, ASCII Codes references or Hot Keys for Windows.

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Libraries

• _OFFSET (function) returns the memory offset of a variable when used with DECLARE DYNAMIC LIBRARY only.
• _OFFSET(variable type) can be used store the value of an offset in memory when using DECLARE DYNAMIC LIBRARY only.

• ALIAS (statement) tells the program that you will use a different name than the name used in the Library file.
• BYVAL (statement) used to pass a parameter's value with sub-procedures from a Library.
• DECLARE LIBRARY allows the use of OS specific, SDL or C++ external library SUB and FUNCTION procedures
• DECLARE DYNAMIC LIBRARY declares DYNAMIC, CUSTOMTYPE or STATIC library(DLL) SUBs or FUNCTIONs.
• END DECLARE required at the END of the block of Library declarations in QB64.

QB64 also supports $INCLUDE text code file Libraries. QB64 does not support QLB Libraries or OBJ files.

See also: C++ Variable Types

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Logical Bitwise Operations

• AND (operator) the bit is set when both bits are set.
• EQV (operator) the bit is set when both are set or both are not set.
• IMP (operator) the bit is set when both are set or both are unset or the second condition bit is set.
• OR (operator) the bit is set when either bit is set.
• NOT (operator) the bit is set when a bit is not set and not set when a bit is set.
• XOR (operator) the bit is set when just one of the bits are set.

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Mathematical Functions and Operations

• _ROUND (function) rounds to the closest EVEN INTEGER, LONG or _INTEGER64 numerical value.

• + addition operation
• - subtraction or negation operation
• * multiplication operation
• / decimal point division operation
• \ integer division operation
• ^ exponential operation
• MOD integer remainder operation

• ABS (function) returns the the positive value of a variable or literal numerical value.
• ATN (function) or arctangent returns the angle in radians of a numerical tangent value.
• CDBL (function) closest double rounding function
• CINT (function) closest integer rounding function
• CLNG (function) closest long integer rounding function
• COS (function) cosine of a radian angle
• CSNG (function) closest single rounding function
• EXP (function) returns the value of e to the power of the parameter used.
• FIX (function) rounds positive or negative values to integer values closer to 0
• INT (function) rounds to lower integer value
• LOG (function) natural logarithm of a specified numerical value.
• SIN (function) sine of a radian angle.
• SQR (function) square root of a positive number.
• TAN (function) returns the ratio of SINe to COSine or tangent value of an angle measured in radians.

See also: Mathematical Operations and Logical Operations

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Memory Handling and Clipboard

• _CLIPBOARD$ (function) returns the current STRING contents of the system Clipboard.
• _CLIPBOARD$ (statement) sets and overwrites the STRING contents of the current system Clipboard.
• _MEM (function) returns _MEM block referring to the largest continuous memory region beginning at a designated variable's offset.
• _MEM (variable type) contains read only dot elements for the OFFSET, SIZE, TYPE and ELEMENTSIZE of a block of memory.
• _MEMCOPY (statement) copies a value from a designated OFFSET and SIZE TO a block of memory at a designated OFFSET.
• _MEMELEMENT (function) returns a _MEM block referring to a variable's memory (but not past it).
• _MEMEXISTS (function) verifies that a memory block exists for a memory variable name or returns zero.
• _MEMFILL (statement) fills a designated memory block OFFSET with a certain SIZE and TYPE of value.
• _MEMFREE (statement) frees a designated memory block in a program. Only free memory once!
• _MEMGET (statement) reads a designated value from a designated memory OFFSET
• _MEMGET (function) returns a value from a designated memory block and OFFSET using a designated variable TYPE.
• _MEMIMAGE (function) returns a _MEM block referring to a designated image handle's memory
• _MEMNEW (function) allocates new memory with a designated SIZE and returns a _MEM block referring to it.
• _MEMPUT (statement) places a designated value into a designated memory _OFFSET
• _MEMSOUND (function) returns a _MEM block referring to a designated sound handle's memory
• _OFFSET (function) returns the memory offset of a variable when used with DECLARE LIBRARY or _MEM only.
• _OFFSET(%& numerical type) can be used store the value of an offset in memory when using DECLARE LIBRARY or _MEM only.

Functions and statements using QB64's emulated 16 bit memory

• DEF SEG (statement) defines the segment address in memory.
• PEEK (function) returns the value that is contained at a certain memory address offset.
• POKE (statement) sets the value of a specified memory address offset.
• SADD (function) returns the address of a STRING variable as an offset from the current data segment.
• VARPTR (function) returns an INTEGER value that is the offset pointer of the memory address within it's segment.
• VARPTR$ (function) returns a STRING representation of a variable's memory address value
• VARSEG (function) returns an INTEGER value that is the segment part of a variable or array memory address.

See also: Screen Memory or Using _OFFSET

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Metacommands

Metacommands are commands that affect a program globally after they are in used. Error checking can be turned OFF or ON.

QB64 Metacommands do NOT allow commenting or REM!

• $CHECKING:OFF/ON (QB64 only) turns event and error checking ON and OFF. ON (default) can only be used after it is OFF.
• $CONSOLE creates a console window throughout the program.
• $SCREENHIDE hides the program window throughout the program until $SCREENSHOW is used.
• $SCREENSHOW displays the main program window throughout the program only after $SCREENHIDE or _SCREENHIDE has been used.

QBasic Metacommands do not require commenting or REM in QB64!

• '$DYNAMIC defines that all arrays are dynamic or changeable in size using DIM or REDIM.
• '$INCLUDE: 'filename$' includes a text library file with procedures to be used in a program. Comment both sides of file name also.
• '$STATIC defines that all arrays are static or unchangeable in size using DIM.

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Mouse Input

• _AXIS (function) returns a SINGLE value between -1 and 1 indicating the maximum distances from device center 0.
• _BUTTON (function) returns -1 when a device button is pressed and 0 when button is released. 2 is the mouse center or scroll button
• _BUTTONCHANGE (function) returns -1 when a device button has been pressed and 1 when released. Zero indicates no change.
• _DEVICE$ (function) returns a STRING expression listing device names and input types of system input devices.
• _DEVICEINPUT (function) returns the _DEVICES number of an _AXIS, _BUTTON or _WHEEL event. Mouse is normally _DEVICEINPUT(2).
• _DEVICES (function) returns the number of input devices found on a computer system. The mouse is normally device 2.
• _EXIT (function) prevents a program user exit and indicates if a user has clicked the close X window button or CTRL + BREAK.
• _LASTAXIS (function) returns the number of axis available on a specified number device listed by _DEVICE$.
• _LASTBUTTON (function) returns the number of buttons available on a specified number device listed by DEVICE$.
• _LASTWHEEL (function) returns the number of scroll wheels available on a specified number device listed by _DEVICE$.
• _MOUSEBUTTON (function) returns whether a specified mouse button number has been clicked. 3 is the mouse center or scroll button
• _MOUSEHIDE (statement) hides the OS mouse pointer from view.
• _MOUSEINPUT (function) must be used to monitor and read all changes in the mouse status.
• _MOUSEMOVE (statement) moves the mouse cursor pointer to a designated coordinate.
• _MOUSEMOVEMENTX (function) returns the relative horizontal position of the mouse cursor.
• _MOUSEMOVEMENTY (function) returns the relative vertical position of the mouse cursor.
• _MOUSESHOW (statement) displays(default) the mouse cursor after it has been hidden.
• _MOUSEWHEEL (function) returns a positive or negative count the mouse scroll wheel clicks since the last read.
• _MOUSEX (function) indicates the current horizontal position of the mouse pointer.
• _MOUSEY (function) indicates the current vertical position of the mouse pointer.
• _SCREENCLICK simulates clicking the mouse at a position on the screen to get focus.
• _WHEEL (function) returns -1 when a device wheel is scrolled up and 1 when scrolled down. Zero indicates no activity.

• CALL ABSOLUTE (statement) used to access Interrupt vector &H33 to work with the mouse. Functions 0 to 3 implemented.
• INTERRUPT (statement) used to access Interrupt vector &H33 to work with the mouse. Functions 0 to 3 implemented.

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Numerical Manipulation and Conversion

• _CV (function) used to convert _MK$ ASCII string values to specified numerical value types.
• _MK$ (function) converts a specified numerical type into an ASCII string value that must be converted back using _CV.
• _PRESERVE (REDIM action) preserves the current contents of an array, when re-dimensioning it.
• _UNSIGNED {numerical type) defines a numerical value as being positive only using QB64.

• ABS (function) returns the the positive value of a variable or literal numerical value.
• ASC (function) returns the ASCII code number of a certain STRING text character or a keyboard press.
• _BIN$ (function) converts the INTEGER part of any value to binary STRING number value.
• CDBL (function) converts a numerical value to the closest DOUBLE-precision value.
• CHR$ (function) returns the character associated with a certain ASCII character code as a STRING.
• CINT (function) returns the closest INTEGER value of a number.
• CLEAR (statement) clears all variable values to 0 or null strings and closes all open files.
• CLNG (function) rounds decimal point numbers up or down to the nearest LONG integer value.
• CSNG (function) converts a numerical value to the closest SINGLE-precision number.
• CVD (function) converts STRING values to DOUBLE numerical values.
• CVDMBF (function) converts a 8-byte Microsoft Binary format string value to a DOUBLE precision number.
• CVI (function) converts 2 byte STRING values to INTEGER numerical values.
• CVL (function) converts 4 byte STRING values to LONG numerical values.
• CVS (function) converts 4 byte STRING values to SINGLE numerical values.
• CVSMBF (function) converts a 4-byte Microsoft Binary format string value to a SINGLE-precision number.
• DIM (statement) used to declare a variable type or dimension a STATIC array.
• ERASE (array statement) clears a STATIC array of all values and totally removes a $DYNAMIC array.
• HEX$ (function) converts the INTEGER part of any value to hexadecimal STRING number value.
• INT (function) rounds a numeric value down to the next whole number or INTEGER value.
• LEN (function) returns the byte size of strings or numerical variables.
• OCT$ (function) converts the INTEGER part of any value to octal STRING number value.
• RANDOMIZE (statement) seeds the RND random number generation sequence.
• REDIM (statement) re-dimensions the number of elements in a dynamic(resizeable) array.
• RND (function) returns a randomly generated number from 0 to .9999999
• SGN (function) returns the sign as -1 for negative, zero for 0 and 1 for positive numerical values.
• STR$ (function) converts a numerical value to a STRING value.
• SWAP (statement) trades the values of two numerical types or strings.
• VAL (function) converts number strings into numerical values until it runs into a non-numeric character.

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Port Input and Output (COM and LPT)

• GET (file I/O statement) reads port data data by byte or record positions.
• LOC (function) finds the current file location or size of a COM port receive buffer.

• OPEN COM (statement) opens a computer serial COMmunications port.
• OUT (statement) sends values to register or port hardware addresses (emulated - limited access).

• PRINT (file statement) writes text and numerical data to a port transmit buffer.
• PUT (file I/O statement) writes data into a RANDOM or BINARY port by byte or record position.

See Port Access Libraries for other ways to access COM and LPT ports..

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Print formatting

• LPRINT USING (statement) prints template formatted STRING text to an LPT or USB printer page.
• PRINT USING (statement) prints template formatted STRING text to the screen.
• PRINT USING (file statement) prints template formatted STRING text to a text file.

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Printer Output (LPT and USB)

• _PRINTIMAGE (statement) prints an image stretched to the size of the paper setting of an LPT or USB printer.

• LPOS (function) returns the current parallel(LPT) printer head position.
• LPRINT (statement) prints text to an LPT or USB printer page.
• LPRINT USING (statement) prints template formatted STRING text to an LPT or USB printer page.

QB64 will use the default system printer selected. _PRINTIMAGE images will be stretched to the paper size setting.

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Program Flow and Loops

• _CONTINUE (statement) skips the remaining lines in a control block (DO/LOOP, FOR/NEXT or WHILE/WEND)
• _DEST (statement) sets the current write image or page. All graphics will go to this image.
• _DEST (function) returns the current write destination image or page.
• _EXIT (function) prevents a user exit and indicates if a user has clicked the close X window button or CTRL + BREAK.
• _SOURCE (statement) establishes the image SOURCE using a designated image handle
• _SOURCE (function) returns the present image _SOURCE handle value.
• _SHELLHIDE (function) returns the code sent by a program exit using END or SYSTEM followed by an INTEGER value.

• CALL (statement) sends code execution to a subroutine procedure in a program.
• CASE (SELECT CASE statement) used within a SELECT CASE block to specify a conditional value of the compared variable.
• CASE ELSE (SELECT CASE statement) used in a SELECT CASE block to specify an alternative to other CASE values.
• CASE IS (SELECT CASE statement) used within a SELECT CASE block to specify a conditional value of the compared variable.
• DO...LOOP (loop statement) used in programs to repeat code or return to the start of a procedure.
• ELSE (statement) used in IF...THEN statements to offer an alternative to other conditional statements.
• ELSEIF (statement) used in IF...THEN block statements to offer an alternative conditional statement.
• END (statement) ENDs a conditional block statement, a sub-procedure or ends the program with "Press any key..."
• END IF (IF statement end) ENDs an IF statement block.
• ERROR (error statement) used to simulate an error in a program.
• EXIT (statement) exits a loop, function or sub-procedure early.
• FOR...NEXT (statement) a counter loop procedure that repeats code a specified number of times.
• GOSUB (statement) send the program to a designated line label procedure in the main module or a SUB procedure.
• GOTO (statement) sends the program to a designated line number or label.
• IF...THEN (statement) a conditional flow statement or block of statements.
• LOOP end of a DO...LOOP procedure that repeats code until or while a condition is true.
• RESUME (error statement) an error statement that can return the program to the NEXT code line or a specific line number.
• RETURN (statement) a sub-procedure statement that returns the program to the code immediately after the procedure call.
• RUN (statement) clears and restarts the program currently in memory or executes another specified program.
• SELECT CASE (statement) determines the program flow by comparing the value of a variable to specific values.
• SHELL (DOS statement) directly accesses the Operating System's command line procedures.
• SLEEP (statement) stops program progression for a specific number of seconds or until a keypress is made.
• STEP (relational statement) is used to step through FOR loop values or use relative graphical coordinates.
• STOP (statement) is used when troubleshooting a program to stop the program at a specified code line.
• SYSTEM (statement) immediately exits a program and closes the program window.
• UNTIL (conditional statement) continues a DO LOOP procedure until a condition is true.
• WHILE (statement) continues a DO LOOP procedure while a condition is true.
• WHILE...WEND (statement) a loop procedure that repeats code while a condition is true.

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Sounds and Music

• _SNDBAL (statement) sets the balance or 3D position of a sound.
• _SNDCLOSE (statement) frees and unloads an open sound using a _SNDOPEN or _SNDCOPY handle.
• _SNDCOPY (function) copies a sound to a new handle so that two or more of the same sound can be played at once.
• _SNDGETPOS (function) returns the current playing position in seconds of a designated sound handle.
• _SNDLEN (function) returns the length of a sound in seconds of a designated sound handle.
• _SNDLIMIT (statement) stops playing a sound after it has been playing for a set number of seconds.
• _SNDLOOP (statement) loops the playing of a specified sound handle.
• _SNDNEW (function) creates a raw empty sound in memory and returns a LONG handle value for later access.
• _SNDOPEN (function) loads a sound file with certain capabilities and returns a handle value.
• _SNDPAUSE (statement) pauses a specified sound handle if it is playing.
• _SNDPAUSED (function) returns the pause status of a specified sound handle.
• _SNDPLAY (statement) plays a designated sound file handle.
• _SNDPLAYCOPY (statement) copies a sound, plays it and automatically closes the copy using a handle parameter
• _SNDPLAYFILE (statement) a simple command to play a sound file with limited options.
• _SNDPLAYING (function) returns whether a sound handle is being played.
• _SNDRATE (function) returns the sample rate frequency per second of the current computer's sound card.
• _SNDRAW (statement) plays sound wave sample frequencies created by a program.
• _SNDRAWDONE (statement) pads a _SNDRAW stream so the final (partially filled) buffer section is played.
• _SNDRAWLEN (function) returns the length, in seconds, of a _SNDRAW sound currently queued.
• _SNDOPENRAW (function) returns a handle to a new, separate _SNDRAW audio stream.
• _SNDSETPOS (statement) changes the current/starting playing position of a sound in seconds.
• _SNDSTOP (statement) stops a playing or paused sound handle.
• _SNDVOL (statement) sets the volume of a sound handle being played.

• BEEP (statement) makes a beep sound when called or CHR$(7) is printed.
• PLAY (music statement) uses a custom string statement to play musical notes.
• SOUND (statement) creates sounds of a specified frequency for a set duration.

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String Text Manipulation and Conversion

• _CLIPBOARD$ (function) returns the current STRING contents of the system Clipboard.
• _CLIPBOARD$ (statement) sets the STRING contents of the current system Clipboard.
• _CONTROLCHR (statement) OFF allows the control characters to be used as text characters. ON(default) can use them as commands.
• _CONTROLCHR (function) returns the current state of _CONTROLCHR as 1 when OFF and 0 when ON.
• _CV (function) used to convert _MK$ ASCII string values to numerical values.
• _MK$ (function) converts any numerical type into an ASCII string value that must be converted back using _CV.
• _STRCMP (function) compares the relationship between two strings.
• _STRICMP (function) compares the relationship between two strings, without regard for case-sensitivity.

• ASC (statement) allows a QB64 program to change a character at any position of a predefined STRING.
• HEX$ (function) returns the base 16 hexadecimal representation of an INTEGER value as a STRING.
• INSTR (function) searches for the first occurance of a search STRING within a string and returns the position.
• LCASE$ (function) changes the uppercase letters of a STRING to lowercase.
• LEFT$ (function) returns a part of a STRING from the start a designated number of character places.
• LEN (function) returns the number of bytes or characters in a STRING value.
• LSET (statement) left-justifies a fixed length string expression based on the size of the STRING.
• LTRIM$ (function) returns a string with all leading spaces removed.
• MID$ (statement) returns a portion of a string from the start position a designated number of characters.
• MKD$ (function) converts a DOUBLE numerical value into an 8 byte ASCII STRING value.
• MKDMBF$ (function) converts a double-precision number to a string containing a value in Microsoft Binary format.
• MKI$ (function) converts a numerical INTEGER value to a 2 byte ASCII string value.
• MKL$ (function) converts a numerical LONG value to a 4 byte ASCII string value.
• MKS$ (function) converts a numerical SINGLE value to a 4 byte ASCII string value.
• MKSMBF$ (function) converts a single-precision number to a string containing a value in Microsoft Binary format.}}
• OCT$ (function) returns the base 8 Octal representation of an INTEGER value.
• RIGHT$ (function) returns a set number of characters in a STRING variable starting from the end.
• RSET (statement) right-justifies a string according to length of the string expression.
• RTRIM$ (function) returns a string with all of the spaces removed at the right end of a string.
• SPACE$ (function) returns a STRING consisting of a number of space characters.
• STR$ (function) converts a numerical value to a STRING.
• STRING ($ variable type) one byte text variable with ASCII code values from 0 to 255.
• STRING$ (function) returns a STRING consisting of a single character repeated a set number of times.
• SWAP (statement) used to exchange two string variable or array element values.
• UCASE$ (function) returns a string with all letters as uppercase.
• VAL (function) converts a string number value to a numerical value.

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Sub procedures and Functions

QBasic and QB64

• CALL (statement) sends code execution to a SUB procedure in a program. Parameter brackets are required when used.
• CALL ABSOLUTE (statement) used to access Interrupts on the computer or execute assembly type procedures.
• CHAIN (statement) changes seamlessly from one program module to another.
• DECLARE (BASIC statement) used to tell that a SUB or FUNCTION is created to be used in the program. NOT USED by QB64!
• END (statement) ends a SUB or FUNCTION procedure.
• EXIT (statement) exits a SUB or FUNCTION procedure early.
• FUNCTION (statement) a procedure that holds ONE return value in the function's name which is a variable type.
• GOSUB (statement) sends the program to a sub program that uses a line number or label.
• $INCLUDE (metacommand) used to insert a source code text file into your program at the point of the insertion.
• INTERRUPT (statement) a built in assembly routine for accessing computer information registers.
• RETURN (statement) used in GOSUB procedures to return to the original call code line.
• RUN (statement) flow statement that clears and restarts the program currently in memory or executes another specified program.
• SHARED (statement) defines a variable or list of variables as shared with the main program module.}}
• SHELL (statement) allows a program to use OS command lines.
• STATIC (statement) defines a variable or list of variables that will retain their values after the sub-procedure is exited.
• SUB (statement) procedures are programs within programs that can return multiple calculations.

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TCP/IP Networking HTTP(S) and Email

All Statements and Functions Compile in QB64 Only!

• _CONNECTED (function) returns the connection status of a TCP/IP connection handle.
• _CONNECTIONADDRESS$ (function) function returns a connected user's STRING IP address value.
• _STATUSCODE (function) gives the HTTP status code of an HTTP response that was opened using _OPENCLIENT.

• _OPENCLIENT (function) connects to a Host on the Internet as a Client and returns the Client status handle.
• _OPENCONNECTION (function) open's a connection from a client that the host has detected and returns a status handle.
• _OPENHOST (function) opens a Host which listens for new connections and returns a Host status handle.

• CLOSE (statement) closes an opened internet connection using the handle assigned in an OPEN statement.

• GET (HTTP statement) reads the response of an HTTP request that was opened using _OPENCLIENT.
• GET (TCP/IP statement) reads a TCP/IP connection port to return a value.

• PUT (TCP/IP statement) sends unformatted(raw) data to an open connection using a user's handle.

See also: Downloading Files

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Text on Screen

• _CONTROLCHR OFF allows ASCII characters 0 to 31 to be used as text characters. ON(default) resets to default usage.
• _FONT (function) creates a new alphablended font handle from a designated image handle
• _FONT (statement) sets the current _LOADFONT function font handle to be used by PRINT or _PRINTSTRING.
• _MAPUNICODE (statement) maps a Unicode value to an ASCII character code value.
• _PRINTSTRING (statement) prints text or custom font strings using graphic column and row coordinate positions.
• _SCREENPRINT (statement) simulates typing text into a Windows program using the keyboard.

• CHR$ (function) returns the text character associated with a certain ASCII character code as a one byte STRING.
• CLS (statement) clears a screen page or the program SCREEN. QB64 can clear with a color.
• COLOR (statement) used to change the color of the text and background in some legacy screen modes.
• CSRLIN (function) returns the current print cursor row position on the screen.
• INPUT (statement) requests a STRING or numerical keyboard entry from a program user.
• KEY LIST (statement) vertically lists all the ON KEY(n) softkey strings associated with each function key F1 to F12.
• LINE INPUT (statement) requests a STRING keyboard entry from a program user.
• LOCATE (statement) locates the screen text row and column positions for a PRINT or INPUT procedure.
• POS (function) returns the current print cursor column position.
• PRINT (statement) prints numeric or string expressions to the program screen.
• PRINT USING (statement) prints template formatted numeric or string values to the program screen.
• SCREEN (statement) sets the screen mode of a program. No statement defaults the program to SCREEN 0 text mode.
• SCREEN (function) returns the ASCII code of a text character or the color attribute at a set text location on the screen.
• SPACE$ (function) returns a string consisting of a number of space characters.
• SPC (function) used in PRINT and LPRINT statements to print or output a number of space characters.
• STR$ (function) returns the STRING representation of a numerical value.
• STRING$(function) returns a STRING consisting of a single character repeated a set number of times.
• TAB (function) used in PRINT and LPRINT statements to move to a specified text column position.
• VIEW PRINT (statement) defines the boundaries of a text viewport PRINT area.
• WIDTH (statement) changes the text dimensions of certain SCREEN modes or printer page widths
• WRITE (screen I/O statement) writes a comma-separated list of values to the screen.

See also: Fonts and Unicode or ASCII Code Table

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Time, Date and Timing

• _AUTODISPLAY (statement) enables the automatic display of the screen image changes previously disabled by _DISPLAY.
• _DELAY (statement) suspends program execution for a SINGLE value of seconds down to milliseconds.
• _DISPLAY (statement) turns off automatic display while only displaying the screen changes when called.
• _FREETIMER (function) returns a free TIMER number for multiple ON TIMER(n) events.
• _KEYDOWN (function) returns whether modifying keys like CTRL, ALT, SHIFT, and any other keys are pressed.
• _KEYHIT (function) returns ASCII one and two byte, SDL Virtual Key and Unicode keyboard key press codes.
• _LIMIT (statement) sets the loop repeat rate of a program to so many per second, relinquishing spare cpu cycles.

• DATE$ (function) returns the present computer date in a mm-dd-yyyy string format

• INKEY$ (function) can be used in a loop to wait for a keypress or a [Ctrl] + letter key combination.
• INPUT (statement) can be used to wait for an [Enter] key press or a text or numerical menu entry.
• INPUT$ (function) can be used to wait for a key press or a fixed length text entry.
• ON KEY(n) (event statement) executes when a keypress or keypress combination occurs.
• ON TIMER(n) (event statement) executes when a timed event occurs. QB64 can use multiple numbered timer events.

• SLEEP (statement) pauses the program for a specified number of seconds or a until a key press is made.
• TIME$ (function) returns the present computer time in a hh:mm:ss 24 hour string format

• TIMER (function) returns the number of seconds past the previous midnite down to a QB64 accuracy of one millisecond.
• TIMER (statement) enables, turns off or stops timer event trapping. In QB64 TIMER(n) FREE can free multiple timers.

• WAIT (statement) normally used to delay program display execution during or after vertical retrace periods.

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Window and Desktop

All Statements and Functions except SCREEN Compile in QB64 Only!

• _COLORCHOOSERDIALOG (function) Displays a standard color picker dialog box and returns a 32-bit RGBA color selected by the user.
• _DESKTOPHEIGHT (function) returns the height of the desktop (not program window).
• _DESKTOPWIDTH (function) returns the width of the desktop (not program window).
• _FULLSCREEN (function) returns the present full screen mode setting number of the screen window.
• _FULLSCREEN (statement) sets the full screen mode of the screen window. Alt + Enter can do it manually.
• _HEIGHT (function) returns the height of a _SCREENIMAGE handle to get the desktop resolution.
• _ICON (statement) creates a program icon from an image file handle created by _LOADIMAGE. Cannot use .ICO files!
• _INPUTBOX$ (function) Displays a prompt in a dialog box, waits for the user to input text or click a button, and returns a string containing the contents of the text box.
• _MESSAGEBOX (function) Displays a message dialog box, which presents a message and returns the button ID clicked by the user.
• _MESSAGEBOX (statement) Displays a message dialog box, which presents a message to the user.
• _NEWIMAGE (statement) function prepares a window image surface and returns the handle value.
• _NOTIFYPOPUP (statement) Shows a system notification popup.
• _OPENFILEDIALOG$ (function) Displays a standard dialog box that prompts the user to open a file.
• $RESIZE (Metacommand) used with ON allows a user to resize the program window where OFF does not.
• _RESIZE (function) returns -1 when a program user attempts to resize the program screen.
• _RESIZEHEIGHT (function) returns the requested new user screen height when $RESIZE:ON allows it.
• _RESIZEWIDTH (function) returns the requested new user screen width when $RESIZE:ON allows it.
• _SAVEFILEDIALOG$ (function) Displays a standard dialog box that prompts the user to save a file.
• _SCREENCLICK simulates clicking the mouse at a position on the screen to get focus.
• _SCREENEXISTS (function) returns a -1 value once a screen has been created.
• $SCREENHIDE (QB64 Metacommand) hides the program window throughout the program until $SCREENSHOW is used.
• _SCREENHIDE (statement) hides the main program window in a section of code until _SCREENSHOW is used.
• _SCREENIMAGE (function) creates an image of the current desktop and returns an image handle.
• _SCREENMOVE (statement) positions the program window on the desktop using designated coordinates or _MIDDLE.
• _SCREENPRINT (statement) simulates typing text into a Windows program using the keyboard.
• $SCREENSHOW (QB64 Metacommand) displays the main program window throughout the program after $SCREENHIDE.
• _SCREENSHOW (statement) displays the main program window in a section of code after _SCREENHIDE has been used.
• _SCREENX (function) returns the current program window's upper left corner column position on the desktop.
• _SCREENY (function) returns the current program window's upper left corner row position on the desktop.
• _SELECTFOLDERDIALOG$ (function) Displays a dialog box that enables the user to select a folder (directory).
• _SMOOTH (function) checks whether the current _FULLSCREEN mode has antialiasing enabled or not.
• _TITLE (statement) sets the program name string in the title bar of the program window.
• _WIDTH (function) returns the width of a _SCREENIMAGE handle to get the desktop resolution.

• SCREEN sets the screen mode of a program. No statement defaults the program to SCREEN 0 text mode.

See also: Console Window, Windows Hot Keys or Focus on Program.

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QB64 Programming Symbols

QB64 and QB Symbols [Note: All symbols below can also be used inside of literal quoted strings except for quotation marks.]

Print, Input or File Formatting

• ; Semicolon after a PRINT stops the invisible cursor at end of the printed value. Can prevent screen rolling!
• , Comma after a PRINT tabs the invisible cursor past the end of the printed value.
• " Quotation mark delimits the ends of a literal STRING value in a PRINT, INPUT or LINE INPUT statement.
• ? Question mark is a shortcut substitute for the PRINT keyword. Will change to PRINT when cursor leaves the code line.

Program Code Markers

• ' Apostrophe denotes a program comment, to ignore a code line or a QBasic Metacommand. Same as using REM.
• , Comma is a statement variable or DATA, SUB or FUNCTION parameter separator.
• Colons can be used to separate two procedure statements on one code line.
• $ Dollar sign prefix denotes a QBasic Metacommand. Only QB64's event $CHECKING should NOT be commented.
• ( ) Parenthesis enclose a math or conditional procedure order, SUB or FUNCTION parameters or to pass by value.
• + Plus concatenation operator MUST be used to combine literal string values in a variable definition.
• " Quotation mark delimits the ends of a literal STRING value. Use CHR$(34) to insert quotes in a text STRING.
• REM or apostrophe are used to make comments or ignore code or precedes a Metacommand.
• _ Underscore at the end of a code line is used to continue a line of code to the next program line in QB64 only.

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Variable Name Type Suffixes

• $ STRING text character type: 1 byte
• ! SINGLE floating decimal point numerical type (4 bytes)
• # DOUBLE floating decimal point numerical type (8 bytes)
• ## _FLOAT QB64 decimal point numerical type (32 bytes)
• ~ _UNSIGNED QB64 whole positive numerical type when it precedes the 6 numerical suffixes below:
• % INTEGER whole numerical type (2 bytes)
• & LONG whole numerical type (4 bytes}
• && _INTEGER64 QB64 whole numerical type (8 bytes)
• ` _BIT QB64 whole numerical type (1 bit)(Key below tilde(~) or CHR$(96))
• %% _BYTE QB64 whole numerical type (1 byte)
• %& _OFFSET QB64 whole numerical pointer address type (any byte size required)

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Numerical Base Prefixes

• &B Binary base 2 Digits 0 or 1 [QB64]
• &O Octal base 8 Digits 0 to 7
• &H Hexadecimal base 16: Digits 0 to F

Mathematical Operations

• + Addition operator or sign
• - Subtraction operator or sign
• * Multiplication operator
• / Division (floating decimal point) operator
• \ Integer division operator
• ^ Exponential operator
• MOD Integer Remainder division operator

Relational Operations

• = (Equal to condition)
• > (Greater than condition)
• < (Less than condition)
• <> (Not equal to condition)
• >= (Greater than or equal to condition)
• <= (Less than or equal to condition)

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QB64 Programming References

Wiki Pages Main Page with Articles and Tutorials QB64 specific keywords (alphabetical) Original QBasic keywords (alphabetical) QB64 OpenGL keywords (alphabetical)

Got a question about something? Frequently Asked Questions about QB64 QB64 Phoenix Edition Community Forum

Links to other QBasic Sites: Pete's QBasic Forum Pete's QBasic Downloads

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