Elemental Intrinsic Function (Generic): Returns the starting position of a substring within a string.
Syntax
Results:
The result is of type integer. If kind is present, the kind parameter of the result is that specified by kind; otherwise, the kind parameter of the result is that of default integer. If the processor cannot represent the result value in the kind of the result, the result is undefined.
If back does not appear (or appears with the value false), the value returned is the minimum value of I such that string (I : I + LEN (substring) - 1) = substring (or zero if there is no such value). If LEN (string) < LEN (substring), zero is returned. If LEN (substring) = zero, 1 is returned.
If back appears with the value true, the value returned is the maximum value of I such that string (I : I + LEN (substring) - 1) = substring (or zero if there is no such value). If LEN(string) < LEN (substring), zero is returned. If LEN (substring) = zero, LEN (string) + 1 is returned.
Specific Name | Argument Type | Result Type |
---|---|---|
INDEX | CHARACTER | INTEGER(4) |
CHARACTER | INTEGER(8) |
Compatibility
CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB
See Also: SCAN
Examples
INDEX ('FORTRAN', 'O', BACK = .TRUE.) has the value 2.
INDEX ('XXXX', " ", BACK = .TRUE.) has the value 5.
The following shows another example:
I = INDEX('banana','an', BACK = .TRUE.) ! returns 4
I = INDEX('banana', 'an') ! returns 2