VARSEG: Difference between revisions
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(Created page with "The '''VARSEG''' function returns an INTEGER value that is the segment part of a variable or array memory address. {{PageSyntax}} :: DEF SEG = VARSEG(variable_name[(start_index)]) * If variablename is not defined before VARPTR or VARSEG is called, the variable is created and its address is returned. * The start index is the lowest index of an array variable when used. * When a string variable, VARSEG returns the segment location address of the first by...") |
TheSnowDog (talk | contribs) m (QBasic capitalisation) Tag: visualeditor |
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* The start index is the lowest index of an array variable when used. | * The start index is the lowest index of an array variable when used. | ||
* When a string variable, VARSEG returns the segment location address of the first byte of the string. | * When a string variable, VARSEG returns the segment location address of the first byte of the string. | ||
* Because many | * Because many QBasic statements change the locations of variables in memory, use the values returned by VARPTR and VARSEG immediately after the functions are used! | ||
* Integer array sizes are limited to 32767 elements when using [[VARSEG]] in QB and '''QB64'''!. Create a larger array using [[_BYTE]]. Example: [[DIM]] [[SHARED]] Memory (65535) AS [[_UNSIGNED]] [[_BYTE]] | * Integer array sizes are limited to 32767 elements when using [[VARSEG]] in QB and '''QB64'''!. Create a larger array using [[_BYTE]]. Example: [[DIM]] [[SHARED]] Memory (65535) AS [[_UNSIGNED]] [[_BYTE]] | ||
* '''Warning: DEF SEG, VARSEG , VARPTR, PEEK or POKE access QB64's emulated 16 bit conventional memory block!''' | * '''Warning: DEF SEG, VARSEG , VARPTR, PEEK or POKE access QB64's emulated 16 bit conventional memory block!''' | ||
Revision as of 10:02, 29 April 2022
The VARSEG function returns an INTEGER value that is the segment part of a variable or array memory address.
Syntax
- DEF SEG = VARSEG(variable_name[(start_index)])
- If variablename is not defined before VARPTR or VARSEG is called, the variable is created and its address is returned.
- The start index is the lowest index of an array variable when used.
- When a string variable, VARSEG returns the segment location address of the first byte of the string.
- Because many QBasic statements change the locations of variables in memory, use the values returned by VARPTR and VARSEG immediately after the functions are used!
- Integer array sizes are limited to 32767 elements when using VARSEG in QB and QB64!. Create a larger array using _BYTE. Example: DIM SHARED Memory (65535) AS _UNSIGNED _BYTE
- Warning: DEF SEG, VARSEG , VARPTR, PEEK or POKE access QB64's emulated 16 bit conventional memory block!
- It is highly recommended that QB64's _MEM memory system be used to avoid running out of memory.
See also: