Remote-processing BASIC 52 Uživatelský manuál stáhnout pdf (Strana 126)

RPBASIC-52 PROGRAMMING GUIDE

2-107

STRING

Syntax: STRING total bytes,string length

Where: total bytes = total num ber of bytes in m emory to allocate

string length = maximum number of bytes in a string

Function: Allocate memory for strings

Mode: Command, run

Use: STRING 56,10 : REM Allocate memory for 5 10-byte strings

Cards: All

DESCRIPTION

Prior to using strings, you m ust use STR ING to allocate mem ory for them. The STRING argument values are

computed by this equation:

total bytes = ((string leng th + 1) * number_of_strings) +1

The only way to recover string memory is with a "STRING 0,0" instruction. String memory is reclaimed and

then reallocated each time you use the STRING operator. Strings are terminated with a carriage return (0DH

or 13) which is the additional byte added to your bytes per string expr.

WARNING:

STRIN G causes RPB ASIC-5 2 to execute the equivalent of a C LEA R instruction sinc e string and numeric

variables occupy the same m emory space. In other words, the STR ING instruction clears all variables,

interrupts and stacks. Allocate string memory early in your program and don't reallocate it unless you can

accept the loss of all variables.

ASC, CHR, STR

ERRORS

MEMORY ALLOCATION Memory not allocated for strings

C-STACK STRING used in a subroutine, clearing the stack.

EXAMPLES

10 STRING 1000,40

20 $(0) = "Up to 40 characters in this string"

100 $(2) = COM$(1)

1 2 ... 121 122 123 124 125 126 127 128 129 130 131 ... 162 163

Žádné komentáře

Remote-processing BASIC 52 Uživatelský manuál Strana 126