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<title>The GNU Fortran Compiler: ASSOCIATED</title>
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<a name="ASSOCIATED"></a>
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<p>
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Next: <a href="ATAN.html#ATAN" accesskey="n" rel="next">ATAN</a>, Previous: <a href="ASINH.html#ASINH" accesskey="p" rel="prev">ASINH</a>, Up: <a href="Intrinsic-Procedures.html#Intrinsic-Procedures" accesskey="u" rel="up">Intrinsic Procedures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
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<a name="ASSOCIATED-_002d_002d_002d-Status-of-a-pointer-or-pointer_002ftarget-pair"></a>
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<h3 class="section">9.20 <code>ASSOCIATED</code> — Status of a pointer or pointer/target pair</h3>
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<a name="index-ASSOCIATED"></a>
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<a name="index-pointer_002c-status"></a>
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<a name="index-association-status"></a>
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<dl compact="compact">
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<dt><em>Description</em>:</dt>
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<dd><p><code>ASSOCIATED(POINTER [, TARGET])</code> determines the status of the pointer
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<var>POINTER</var> or if <var>POINTER</var> is associated with the target <var>TARGET</var>.
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</p>
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</dd>
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<dt><em>Standard</em>:</dt>
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<dd><p>Fortran 95 and later
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</p>
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</dd>
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<dt><em>Class</em>:</dt>
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<dd><p>Inquiry function
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</p>
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</dd>
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<dt><em>Syntax</em>:</dt>
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<dd><p><code>RESULT = ASSOCIATED(POINTER [, TARGET])</code>
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</p>
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</dd>
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<dt><em>Arguments</em>:</dt>
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<dd><table>
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<tr><td width="15%"><var>POINTER</var></td><td width="70%"><var>POINTER</var> shall have the <code>POINTER</code> attribute
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and it can be of any type.</td></tr>
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<tr><td width="15%"><var>TARGET</var></td><td width="70%">(Optional) <var>TARGET</var> shall be a pointer or
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a target. It must have the same type, kind type parameter, and
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array rank as <var>POINTER</var>.</td></tr>
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</table>
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<p>The association status of neither <var>POINTER</var> nor <var>TARGET</var> shall be
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undefined.
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</p>
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</dd>
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<dt><em>Return value</em>:</dt>
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<dd><p><code>ASSOCIATED(POINTER)</code> returns a scalar value of type <code>LOGICAL(4)</code>.
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There are several cases:
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</p><dl compact="compact">
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<dt>(A) When the optional <var>TARGET</var> is not present then</dt>
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<dd><p><code>ASSOCIATED(POINTER)</code> is true if <var>POINTER</var> is associated with a target; otherwise, it returns false.
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</p></dd>
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<dt>(B) If <var>TARGET</var> is present and a scalar target, the result is true if</dt>
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<dd><p><var>TARGET</var> is not a zero-sized storage sequence and the target associated with <var>POINTER</var> occupies the same storage units. If <var>POINTER</var> is
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disassociated, the result is false.
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</p></dd>
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<dt>(C) If <var>TARGET</var> is present and an array target, the result is true if</dt>
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<dd><p><var>TARGET</var> and <var>POINTER</var> have the same shape, are not zero-sized arrays,
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are arrays whose elements are not zero-sized storage sequences, and
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<var>TARGET</var> and <var>POINTER</var> occupy the same storage units in array element
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order.
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As in case(B), the result is false, if <var>POINTER</var> is disassociated.
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</p></dd>
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<dt>(D) If <var>TARGET</var> is present and an scalar pointer, the result is true</dt>
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<dd><p>if <var>TARGET</var> is associated with <var>POINTER</var>, the target associated with
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<var>TARGET</var> are not zero-sized storage sequences and occupy the same storage
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units.
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The result is false, if either <var>TARGET</var> or <var>POINTER</var> is disassociated.
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</p></dd>
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<dt>(E) If <var>TARGET</var> is present and an array pointer, the result is true if</dt>
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<dd><p>target associated with <var>POINTER</var> and the target associated with <var>TARGET</var>
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have the same shape, are not zero-sized arrays, are arrays whose elements are
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not zero-sized storage sequences, and <var>TARGET</var> and <var>POINTER</var> occupy
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the same storage units in array element order.
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The result is false, if either <var>TARGET</var> or <var>POINTER</var> is disassociated.
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</p></dd>
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</dl>
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</dd>
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<dt><em>Example</em>:</dt>
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<dd><div class="smallexample">
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<pre class="smallexample">program test_associated
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implicit none
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real, target :: tgt(2) = (/1., 2./)
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real, pointer :: ptr(:)
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ptr => tgt
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if (associated(ptr) .eqv. .false.) call abort
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if (associated(ptr,tgt) .eqv. .false.) call abort
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end program test_associated
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</pre></div>
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</dd>
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<dt><em>See also</em>:</dt>
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<dd><p><a href="NULL.html#NULL">NULL</a>
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</p></dd>
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</dl>
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<p>
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Next: <a href="ATAN.html#ATAN" accesskey="n" rel="next">ATAN</a>, Previous: <a href="ASINH.html#ASINH" accesskey="p" rel="prev">ASINH</a>, Up: <a href="Intrinsic-Procedures.html#Intrinsic-Procedures" accesskey="u" rel="up">Intrinsic Procedures</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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