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Purpose |
Replace characters in a
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Syntax |
MID$(string_var, start& [, length&]) = replacement |
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Remarks |
start& and length& are numeric variables or expressions. As a statement, MID$ replaces length& characters of string_var, beginning at character position start&, with the contents of replacement string. If length& is included, it determines how many characters of replacement string are inserted into string_var. If length& is omitted, all of replacement string is used. If length& is negative, it is interpreted as LEN(string_var)-ABS(length&). For example, MID$("ABCDEFGHIJK",3,-7) = "*******" yields "AB****GHIJK". If start& is negative, the starting position is assumed to be start& characters from the end of the string. MID$("abcde", -3, 2) = "123" yields "ab12e", while the statement MID$("abcde", -3) = "123" yields "ab123". The replacement will never extend past the end of the original string_var; that is, MID$ never alters the length of a string. For a similar function that can alter the length of a string, please refer to the REPLACE statement. |
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Restrictions |
If start& evaluates to a position outside of the string on either side, or if start& is zero, no operation is performed. The MID$ statement cannot be used to extend the length of a string. If start is beyond the end of a string, the statement is ignored. |
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See also |
BUILD$, INSTR, LTRIM$, MID$ function, REMOVE$, REPLACE, RTRIM$, TALLY, TRIM$, VERIFY |
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Example |
DummyString$ = "1234567890" FOR M = 1 TO 10 TestString$ = DummyString$ MID$(TestString$,1,M) = "PowerBASIC" NEXT M |
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Result |
P234567890 Po34567890 Pow4567890 Powe567890 ... PowerBAS90 PowerBASI0 PowerBASIC |