NULL example program

<Example Program>

Program null_example
  Real, Pointer :: x(:,:) => Null()
  Print 1, Associated(x)
  Allocate(x(3,4))
  Print 1, Associated(x)
  x => Null()
  Print 1, Associated(x)
1 Format (1X, 'X is now associated: ', L1)
End Program

Execution Results

 X is now associated: F
 X is now associated: T
 X is now associated: F