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