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| <h3 class="section">8.195 <code>PRESENT</code> — Determine whether an optional dummy argument is specified</h3> |
| |
| <p><a name="index-PRESENT-950"></a> |
| <dl> |
| <dt><em>Description</em>:<dd>Determines whether an optional dummy argument is present. |
| |
| <br><dt><em>Standard</em>:<dd>Fortran 95 and later |
| |
| <br><dt><em>Class</em>:<dd>Inquiry function |
| |
| <br><dt><em>Syntax</em>:<dd><code>RESULT = PRESENT(A)</code> |
| |
| <br><dt><em>Arguments</em>:<dd> |
| <p><table summary=""><tr align="left"><td valign="top" width="15%"><var>A</var> </td><td valign="top" width="70%">May be of any type and may be a pointer, scalar or array |
| value, or a dummy procedure. It shall be the name of an optional dummy argument |
| accessible within the current subroutine or function. |
| <br></td></tr></table> |
| |
| <br><dt><em>Return value</em>:<dd>Returns either <code>TRUE</code> if the optional argument <var>A</var> is present, or |
| <code>FALSE</code> otherwise. |
| |
| <br><dt><em>Example</em>:<dd> |
| <pre class="smallexample"> PROGRAM test_present |
| WRITE(*,*) f(), f(42) ! "F T" |
| CONTAINS |
| LOGICAL FUNCTION f(x) |
| INTEGER, INTENT(IN), OPTIONAL :: x |
| f = PRESENT(x) |
| END FUNCTION |
| END PROGRAM |
| </pre> |
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