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Purpose |
Search a
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Syntax |
y& = INSTR([n&,] MainString, [ANY] MatchString) |
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Remarks |
INSTR returns the position of MatchString within MainString. n& is an optional Long-integer expression, and MainString and MatchString are string variables, expressions, or string equates/constants. If n& is greater than zero (positive), MainString is searched from left to right, starting at character position n&, for the first occurrence of MatchString. If n& is less than zero (negative), MainString is searched from right to left for the first occurrence of MatchString. If -1, the search begins at the last position. If -2, the search begins at the second to last position, and so forth. x& = INSTR(-2, "efcdef", ANY "ef") This returns 5. If MatchString is not found in the specified portion of MainString, or n& evaluates outside of MatchString, INSTR returns 0. If MatchString is null (an empty string), INSTR returns 1 (if n& not specified) or n& (if n& is specified). |
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ANY |
If the ANY keyword is included, MatchString specifies a list of single characters to be searched for individually, a match on any one of which will conclude the search operation, and return the position of the match. INSTR is case-sensitive, meaning that upper-case and lower-case letters must match exactly in MatchString and MainString. |
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Restrictions |
If n& is zero, INSTR will return zero. |
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See also |
EXTRACT$, LCASE$, LEFT$, LTRIM$, MID$, RIGHT$, RTRIM$, TALLY, TRIM$, UCASE$, VERIFY |
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Example |
' x$ = first command-line argument, assuming ' spaces, commas, periods, and tabs are valid ' delimiters IF INSTR(COMMAND$, ANY " ,." + CHR$(9)) > 0 THEN x$ = "There is more than one command-line argument" ELSE x$ = "There is at most one command-line argument" END IF |