8.256 VERIFY — Scan a string for characters not a given set

Description:

Verifies that all the characters in STRING belong to the set of characters in SET.

If BACK is either absent or equals FALSE, this function returns the position of the leftmost character of STRING that is not in SET. If BACK equals TRUE, the rightmost position is returned. If all characters of STRING are found in SET, the result is zero.

Standard:

Fortran 95 and later, with KIND argument Fortran 2003 and later

Class:

Elemental function

Syntax:

RESULT = VERIFY(STRING, SET[, BACK [, KIND]])

Arguments:

STRING	Shall be of type CHARACTER.
SET	Shall be of type CHARACTER.
BACK	(Optional) shall be of type LOGICAL.
KIND	(Optional) An INTEGER initialization expression indicating the kind parameter of the result.

Return value:

The return value is of type INTEGER and of kind KIND. If KIND is absent, the return value is of default integer kind.

Example:

PROGRAM test_verify
  WRITE(*,*) VERIFY("FORTRAN", "AO")           ! 1, found 'F'
  WRITE(*,*) VERIFY("FORTRAN", "FOO")          ! 3, found 'R'
  WRITE(*,*) VERIFY("FORTRAN", "C++")          ! 1, found 'F'
  WRITE(*,*) VERIFY("FORTRAN", "C++", .TRUE.)  ! 7, found 'N'
  WRITE(*,*) VERIFY("FORTRAN", "FORTRAN")      ! 0' found none
END PROGRAM

See also:

SCAN, INDEX intrinsic