MID$ (statement)

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Revision as of 22:41, 20 June 2010 by imported>Clippy
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The MID$ statement overwrites a portion of a previously defined STRING.

Syntax: MID$(basestring$, start_position%[, bytes%]) = string_to_add$

  • String value is any literal or variable STRING and/or ASCII character values.
  • Start position specifies the string character position to start the overwrite. Cannot be 0 or an Illegal function call error will occur!
  • The byte length is optional. Excess statement string characters or byte lenghts are ignored.
  • The string value to be placed in the string should be as long as the byte length reserved.
  • The length of the original string is NOT changed in any case! Excess characters will not be in the string value returned.

Example: Using INSTR to locate the string positions and a MID$ statement to change the words.

text$ = "The cats and dogs where playing, even though dogs don't like cats." start% = 1 ' start cannot be 0 when used in the INSTR function! DO position% = INSTR(start%, text$, "dog") IF position% THEN ' when position is a value greater than 0 MID$(text$, position%, 3) = "rat" ' changes "dog" to "rat" when found start% = position% + 1 ' advance one position to search rest of string END IF LOOP UNTIL position% = 0 ' no other matches found PRINT a$

The cats and rats were playing, even though rats don't like cats.

See also:

MID$, INSTR, ASCII, STR$, HEX$, Bitmaps (example)


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