LF Fortran 95

PRESENT Function

Description

The PRESENT function determines whether or not an optional argument is present.

Syntax

PRESENT (a)

Arguments

a is INTENT(IN) and must be an optional dummy argument of the procedure in which the PRESENT function appears.

Result

The result is a scalar default LOGICAL.

Its value is true if the actual argument corresponding to a was provided in the invocation of the procedure in which the PRESENT function appears; otherwise, it is false.

Example

function fun1(a,b) real :: fun1,a real,optional :: b if(present(b)) then ! don't reference b unless fun1=a+b ! it is present else fun1=a end if end function

See Also

OPTIONAL Statement