Constants

Starting with QB64-PE v4.0.0 the compiler provides a huge set of preset CONST values. The list of constants shown below is available for use in every compiled program. Note that the names of all these preset constants have to be preceeded with an underscore, just like all the other QB64(PE) specific keywords.

Libray makers can use the the also new _QB64PE_ precompiler flag in their include files to find out if these new preset constants are available for use or not.

Note

You cannot copy and paste the following list into the IDE. Due to the use of underscore names the IDE would immediately throw "Invalid name" errors. Those names can only be defined internally.
We just made the list in this familiar program like format, so you can easily see how the constants are defined and which OS/BITS relevant distinctions are made.

'Boolean values
CONST _TRUE = -1, _FALSE = 0
'Relations (e.g. SGN and _STRCMP, _STRICMP)
CONST _LESS = -1, _EQUAL = 0, _GREATER = 1
'State values (_OPENHOST/CLIENT/CONNECTION, _LOAD/COPYIMAGE, _LOADFONT, _SNDOPEN[RAW])
CONST _HOST_FAILED = 0, _CLIENT_FAILED = 0, _CONNECTION_FAILED = 0
CONST _INVALID_IMAGE = -1, _LOADFONT_FAILED = 0, _SNDOPEN_FAILED = 0
'Some strings (see also _ASC* and _CHR* section below)
CONST _STR_EMPTY = ""
CONST _STR_CRLF = CHR$(13) + CHR$(10), _STR_LF = CHR$(10) 'for native use _STR_NAT_EOL below
$IF WIN THEN
    CONST _STR_NAT_EOL = CHR$(13) + CHR$(10)
$ELSE
    CONST _STR_NAT_EOL = CHR$(10)
$END IF 
'Some math
CONST _E## = EXP(1.0##)

'Logging values for _LOGMINLEVEL
CONST _LOG_TRACE = 1
CONST _LOG_INFO = 2
CONST _LOG_WARN = 3
CONST _LOG_ERROR = 4
CONST _LOG_NONE = 5

'Base time values
CONST _SECS_IN_MIN = 60, _MINS_IN_HOUR = 60, _HOURS_IN_DAY = 24
CONST _DAYS_IN_WEEK = 7, _DAYS_IN_YEAR = 365
'Derived time values
CONST _SECS_IN_HOUR = _MINS_IN_HOUR * _SECS_IN_MIN
CONST _SECS_IN_DAY = _HOURS_IN_DAY * _SECS_IN_HOUR
CONST _SECS_IN_WEEK = _DAYS_IN_WEEK * _SECS_IN_DAY
CONST _SECS_IN_YEAR = _DAYS_IN_YEAR * _SECS_IN_DAY
CONST _SECS_IN_LEAPYEAR = _SECS_IN_YEAR + _SECS_IN_DAY
CONST _MINS_IN_DAY = _HOURS_IN_DAY * _MINS_IN_HOUR
CONST _MINS_IN_WEEK = _DAYS_IN_WEEK * _MINS_IN_DAY
CONST _MINS_IN_YEAR = _DAYS_IN_YEAR * _MINS_IN_DAY
CONST _MINS_IN_LEAPYEAR = _MINS_IN_YEAR + _MINS_IN_DAY
CONST _HOURS_IN_WEEK = _DAYS_IN_WEEK * _HOURS_IN_DAY
CONST _HOURS_IN_YEAR = _DAYS_IN_YEAR * _HOURS_IN_DAY
CONST _HOURS_IN_LEAPYEAR = _HOURS_IN_YEAR + _HOURS_IN_DAY
CONST _DAYS_IN_LEAPYEAR = _DAYS_IN_YEAR + 1
CONST _WEEKS_IN_YEAR = _DAYS_IN_YEAR / _DAYS_IN_WEEK
CONST _WEEKS_IN_LEAPYEAR = _DAYS_IN_LEAPYEAR / _DAYS_IN_WEEK

'Binary size factors
CONST _ONE_KB = 1024 '            ' 2^10
CONST _ONE_MB = _ONE_KB * _ONE_KB ' 2^20
CONST _ONE_GB = _ONE_MB * _ONE_KB ' 2^30
CONST _ONE_TB = _ONE_GB * _ONE_KB ' 2^40
CONST _ONE_PB = _ONE_TB * _ONE_KB ' 2^50
CONST _ONE_EB = _ONE_PB * _ONE_KB ' 2^60

'Sizes of elementary integer types (in bytes)
CONST _SIZE_OF_BYTE = 1
CONST _SIZE_OF_INTEGER = 2
CONST _SIZE_OF_LONG = 4
CONST _SIZE_OF_INTEGER64 = 8
'Sizes of elementary floating point types (in bytes)
CONST _SIZE_OF_SINGLE = 4
CONST _SIZE_OF_DOUBLE = 8
CONST _SIZE_OF_FLOAT = 32
'Sizes of elementary pointer types (in bytes)
$IF 32BIT THEN
    CONST _SIZE_OF_OFFSET = 4
$ELSE
    CONST _SIZE_OF_OFFSET = 8
$END IF 

'Limits of elementary integer types (min/max values)
CONST _BIT_MIN` = -1, _BIT_MAX` = 0
CONST _UBIT_MIN~` = 0, _UBIT_MAX~` = 1
CONST _BYTE_MIN%% = -128, _BYTE_MAX%% = 127
CONST _UBYTE_MIN~%% = 0, _UBYTE_MAX~%% = 255
CONST _INTEGER_MIN% = -32768, _INTEGER_MAX% = 32767
CONST _UINTEGER_MIN~% = 0, _UINTEGER_MAX~% = 65535
CONST _LONG_MIN& = -2147483648, _LONG_MAX& = 2147483647
CONST _ULONG_MIN~& = 0, _ULONG_MAX~& = 4294967295
CONST _INTEGER64_MIN&& = -9223372036854775808, _INTEGER64_MAX&& = 9223372036854775807
CONST _UINTEGER64_MIN~&& = 0, _UINTEGER64_MAX~&& = 18446744073709551615
'Limits of elementary floating point types (min/max values)
CONST _SINGLE_MIN! = -3.402823E+38, _SINGLE_MAX! = 3.402823E+38
CONST _SINGLE_MIN_FRAC! = 1.175494E-38
CONST _DOUBLE_MIN# = -1.797693134862315D+308, _DOUBLE_MAX# = 1.797693134862315D+308
CONST _DOUBLE_MIN_FRAC# = 2.225073858507201D-308
CONST _FLOAT_MIN## = -1.189731495357231765F+4932, _FLOAT_MAX## = 1.189731495357231765F+4932
CONST _FLOAT_MIN_FRAC## = 3.362103143112093506F-4932
'Limits of elementary pointer types (min/max values)
$IF 32BIT THEN
    CONST _OFFSET_MIN& = -2147483648, _OFFSET_MAX& = 2147483647
    CONST _UOFFSET_MIN~& = 0, _UOFFSET_MAX~& = 4294967295
$ELSE
    CONST _OFFSET_MIN&& = -9223372036854775808, _OFFSET_MAX&& = 9223372036854775807
    CONST _UOFFSET_MIN~&& = 0, _UOFFSET_MAX~&& = 18446744073709551615
$END IF 

'Control char codes (ASC + CHR$)
CONST _ASC_NUL = 0, _CHR_NUL = CHR$(0) '     Null
CONST _ASC_SOH = 1, _CHR_SOH = CHR$(1) '     Start of Heading
CONST _ASC_STX = 2, _CHR_STX = CHR$(2) '     Start of Text
CONST _ASC_ETX = 3, _CHR_ETX = CHR$(3) '     End of Text
CONST _ASC_EOT = 4, _CHR_EOT = CHR$(4) '     End of Transmission
CONST _ASC_ENQ = 5, _CHR_ENQ = CHR$(5) '     Enquiry
CONST _ASC_ACK = 6, _CHR_ACK = CHR$(6) '     Acknowledge
CONST _ASC_BEL = 7, _CHR_BEL = CHR$(7) '     Bell
CONST _ASC_BS = 8, _CHR_BS = CHR$(8) '       Backspace
CONST _ASC_HT = 9, _CHR_HT = CHR$(9) '       Horizontal Tab
CONST _ASC_LF = 10, _CHR_LF = CHR$(10) '     Line Feed
CONST _ASC_VT = 11, _CHR_VT = CHR$(11) '     Vertical Tab
CONST _ASC_FF = 12, _CHR_FF = CHR$(12) '     Form Feed
CONST _ASC_CR = 13, _CHR_CR = CHR$(13) '     Carriage Return
CONST _ASC_SO = 14, _CHR_SO = CHR$(14) '     Shift Out
CONST _ASC_SI = 15, _CHR_SI = CHR$(15) '     Shift In
CONST _ASC_DLE = 16, _CHR_DLE = CHR$(16) '   Data Link Escape
CONST _ASC_DC1 = 17, _CHR_DC1 = CHR$(17) '   Device Control 1
CONST _ASC_DC2 = 18, _CHR_DC2 = CHR$(18) '   Device Control 2
CONST _ASC_DC3 = 19, _CHR_DC3 = CHR$(19) '   Device Control 3
CONST _ASC_DC4 = 20, _CHR_DC4 = CHR$(20) '   Device Control 4
CONST _ASC_NAK = 21, _CHR_NAK = CHR$(21) '   Negative Acknowledge
CONST _ASC_SYN = 22, _CHR_SYN = CHR$(22) '   Synchronous Idle
CONST _ASC_ETB = 23, _CHR_ETB = CHR$(23) '   End of Transmission Block
CONST _ASC_CAN = 24, _CHR_CAN = CHR$(24) '   Cancel
CONST _ASC_EM = 25, _CHR_EM = CHR$(25) '     End of Medium
CONST _ASC_SUB = 26, _CHR_SUB = CHR$(26) '   Substitute
CONST _ASC_ESC = 27, _CHR_ESC = CHR$(27) '   Escape
CONST _ASC_FS = 28, _CHR_FS = CHR$(28) '     File Separator
CONST _ASC_GS = 29, _CHR_GS = CHR$(29) '     Group Separator
CONST _ASC_RS = 30, _CHR_RS = CHR$(30) '     Record Separator
CONST _ASC_US = 31, _CHR_US = CHR$(31) '     Unit Separator
CONST _ASC_DEL = 127, _CHR_DEL = CHR$(127) ' Delete
'Normal char codes (exluding 0-9/Aa-Zz)
CONST _ASC_SPACE = 32, _CHR_SPACE = CHR$(32)
CONST _ASC_EXCLAMATION = 33, _CHR_EXCLAMATION = CHR$(33) '               !
CONST _ASC_QUOTE = 34, _CHR_QUOTE = CHR$(34) '                           "
CONST _ASC_HASH = 35, _CHR_HASH = CHR$(35) '                             #
CONST _ASC_DOLLAR = 36, _CHR_DOLLAR = CHR$(36) '                         $
CONST _ASC_PERCENT = 37, _CHR_PERCENT = CHR$(37) '                       %
CONST _ASC_AMPERSAND = 38, _CHR_AMPERSAND = CHR$(38) '                   &
CONST _ASC_APOSTROPHE = 39, _CHR_APOSTROPHE = CHR$(39) '                 '
CONST _ASC_LEFTBRACKET = 40, _CHR_LEFTBRACKET = CHR$(40) '               (
CONST _ASC_RIGHTBRACKET = 41, _CHR_RIGHTBRACKET = CHR$(41) '             )
CONST _ASC_ASTERISK = 42, _CHR_ASTERISK = CHR$(42) '                     *
CONST _ASC_PLUS = 43, _CHR_PLUS = CHR$(43) '                             +
CONST _ASC_COMMA = 44, _CHR_COMMA = CHR$(44) '                           ,
CONST _ASC_MINUS = 45, _CHR_MINUS = CHR$(45) '                           -
CONST _ASC_FULLSTOP = 46, _CHR_FULLSTOP = CHR$(46) '                     .
CONST _ASC_FORWARDSLASH = 47, _CHR_FORWARDSLASH = CHR$(47) '             /
CONST _ASC_COLON = 58, _CHR_COLON = CHR$(58) '                           :
CONST _ASC_SEMICOLON = 59, _CHR_SEMICOLON = CHR$(59) '                   ;
CONST _ASC_LESSTHAN = 60, _CHR_LESSTHAN = CHR$(60) '                     <
CONST _ASC_EQUAL = 61, _CHR_EQUAL = CHR$(61) '                           =
CONST _ASC_GREATERTHAN = 62, _CHR_GREATERTHAN = CHR$(62) '               >
CONST _ASC_QUESTION = 63, _CHR_QUESTION = CHR$(63) '                     ?
CONST _ASC_ATSIGN = 64, _CHR_ATSIGN = CHR$(64) '                         @
CONST _ASC_LEFTSQUAREBRACKET = 91, _CHR_LEFTSQUAREBRACKET = CHR$(91) '   [
CONST _ASC_BACKSLASH = 92, _CHR_BACKSLASH = CHR$(92) '                   \
CONST _ASC_RIGHTSQUAREBRACKET = 93, _CHR_RIGHTSQUAREBRACKET = CHR$(93) ' ]
CONST _ASC_CARET = 94, _CHR_CARET = CHR$(94) '                           ^
CONST _ASC_UNDERSCORE = 95, _CHR_UNDERSCORE = CHR$(95) '                 _
CONST _ASC_GRAVE = 96, _CHR_GRAVE = CHR$(96) '                           `
CONST _ASC_LEFTCURLYBRACKET = 123, _CHR_LEFTCURLYBRACKET = CHR$(123) '   {
CONST _ASC_VERTICALBAR = 124, _CHR_VERTICALBAR = CHR$(124) '             |
CONST _ASC_RIGHTCURLYBRACKET = 125, _CHR_RIGHTCURLYBRACKET = CHR$(125) ' }
CONST _ASC_TILDE = 126, _CHR_TILDE = CHR$(126) '                         ~

'_KEYDOWN/_KEYHIT codes
CONST _KEY_LSHIFT = 100304, _KEY_RSHIFT = 100303
CONST _KEY_LCTRL = 100306, _KEY_RCTRL = 100305
CONST _KEY_LALT = 100308, _KEY_RALT = 100307
CONST _KEY_LAPPLE = 100310, _KEY_RAPPLE = 100309
CONST _KEY_F1 = 15104, _KEY_F2 = 15360, _KEY_F3 = 15616, _KEY_F4 = 15872
CONST _KEY_F5 = 16128, _KEY_F6 = 16384, _KEY_F7 = 16640, _KEY_F8 = 16896
CONST _KEY_F9 = 17152, _KEY_F10 = 17408, _KEY_F11 = 34048, _KEY_F12 = 34304
CONST _KEY_INSERT = 20992, _KEY_DELETE = 21248
CONST _KEY_HOME = 18176, _KEY_END = 20224
CONST _KEY_PAGEUP = 18688, _KEY_PAGEDOWN = 20736
CONST _KEY_LEFT = 19200, _KEY_RIGHT = 19712, _KEY_UP = 18432, _KEY_DOWN = 20480
CONST _KEY_BACKSPACE = 8, _KEY_TAB = 9, _KEY_ENTER = 13, _KEY_ESC = 27

'ERROR codes (ERROR n triggers an error, n = ERR will return the last occurred error)
CONST _ERR_NONE = 0 'for compare with ERR only !!
CONST _ERR_NEXT_WITHOUT_FOR = 1
CONST _ERR_SYNTAX_ERROR = 2
CONST _ERR_RETURN_WITHOUT_GOSUB = 3
CONST _ERR_OUT_OF_DATA = 4
CONST _ERR_ILLEGAL_FUNCTION_CALL = 5
CONST _ERR_OVERFLOW = 6
CONST _ERR_OUT_OF_MEMORY = 7
CONST _ERR_LABEL_NOT_DEFINED = 8
CONST _ERR_SUBSCRIPT_OUT_OF_RANGE = 9
CONST _ERR_DUPLICATE_DEFINITION = 10
CONST _ERR_DIVISION_BY_ZERO = 11
CONST _ERR_ILLEGAL_IN_DIRECT_MODE = 12
CONST _ERR_TYPE_MISMATCH = 13
CONST _ERR_OUT_OF_STRING_SPACE = 14
CONST _ERR_STRING_FORMULA_TOO_COMPLEX = 16
CONST _ERR_CANNOT_CONTINUE = 17
CONST _ERR_FUNCTION_NOT_DEFINED = 18
CONST _ERR_NO_RESUME = 19
CONST _ERR_RESUME_WITHOUT_ERROR = 20
CONST _ERR_DEVICE_TIMEOUT = 24
CONST _ERR_DEVICE_FAULT = 25
CONST _ERR_FOR_WITHOUT_NEXT = 26
CONST _ERR_OUT_OF_PAPER = 27
CONST _ERR_WHILE_WITHOUT_WEND = 29
CONST _ERR_WEND_WITHOUT_WHILE = 30
CONST _ERR_DUPLICATE_LABEL = 33
CONST _ERR_SUBPROGRAM_NOT_DEFINED = 35
CONST _ERR_ARGUMENT_COUNT_MISMATCH = 37
CONST _ERR_ARRAY_NOT_DEFINED = 38
CONST _ERR_VARIABLE_REQUIRED = 40
CONST _ERR_FIELD_OVERFLOW = 50
CONST _ERR_INTERNAL_ERROR = 51
CONST _ERR_BAD_FILE_NAME_OR_NUMBER = 52
CONST _ERR_FILE_NOT_FOUND = 53
CONST _ERR_BAD_FILE_MODE = 54
CONST _ERR_FILE_ALREADY_OPEN = 55
CONST _ERR_FIELD_STATEMENT_ACTIVE = 56
CONST _ERR_DEVICE_IO_ERROR = 57
CONST _ERR_FILE_ALREADY_EXISTS = 58
CONST _ERR_BAD_RECORD_LENGTH = 59
CONST _ERR_DISK_FULL = 61
CONST _ERR_INPUT_PAST_END_OF_FILE = 62
CONST _ERR_BAD_RECORD_NUMBER = 63
CONST _ERR_BAD_FILE_NAME = 64
CONST _ERR_TOO_MANY_FILES = 67
CONST _ERR_DEVICE_UNAVAILABLE = 68
CONST _ERR_COMMUNICATION_BUFFER_OVERFLOW = 69
CONST _ERR_PERMISSION_DENIED = 70
CONST _ERR_DISK_NOT_READY = 71
CONST _ERR_DISK_MEDIA_ERROR = 72
CONST _ERR_FEATURE_UNAVAILABLE = 73
CONST _ERR_RENAME_ACROSS_DISKS = 74
CONST _ERR_PATH_FILE_ACCESS_ERROR = 75
CONST _ERR_PATH_NOT_FOUND = 76
CONST _ERR_INVALID_HANDLE = 258

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