VERIFY(STRING, SET, BACK, KIND)

Purpose

Verify that a set of characters contains all the characters in a string by identifying the position of the first character in a string of characters that does not appear in a given set of characters.

Class

Elemental function

Argument type and attributes

STRING

An INTENT(IN) CHARACTER

SET

An INTENT(IN) CHARACTER with the same kind type parameter as STRING.

BACK (optional)

An INTENT(IN) LOGICAL

KIND (optional)

An INTENT(IN) INTEGER scalar. The actual argument corresponding to KIND must be a constant expression.

Result type and attributes

• It is of type integer
• If KIND is present, the KIND type parameter is that specified by the value of KIND; otherwise, the KIND type parameter is that of default integer type.

Result value

• Case (i): If BACK is absent or present with the value .FALSE. and if STRING contains at least one character that is not in SET, the value of the result is the position of the leftmost character of STRING that is not in SET.
• Case (ii): If BACK is present with the value .TRUE. and if STRING contains at least one character that is not in SET, the value of the result is the position of the rightmost character of STRING that is not in SET.
• Case (iii): The value of the result is zero if each character in STRING is in SET or if STRING has zero length.