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<h1 class="refname">ReflectionParameter::getDefaultValueConstantName</h1>
<p class="verinfo">(PHP 5 >= 5.4.6, PHP 7)</p><p class="refpurpose"><span class="refname">ReflectionParameter::getDefaultValueConstantName</span> — <span class="dc-title">Returns the default value's constant name if default value is constant or null</span></p>
</div>
<div class="refsect1 description" id="refsect1-reflectionparameter.getdefaultvalueconstantname-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span> <span class="type">string</span> <span class="methodname"><strong>ReflectionParameter::getDefaultValueConstantName</strong></span>
( <span class="methodparam">void</span>
)</div>
<p class="para rdfs-comment">
Returns the default value's constant name of the parameter of a user-defined
function or method, if default value is constant or null.
If the parameter is not optional a <a href="class.reflectionexception.html" class="classname">ReflectionException</a>
will be thrown.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-reflectionparameter.getdefaultvalueconstantname-parameters">
<h3 class="title">Parameters</h3>
<p class="para">This function has no parameters.</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-reflectionparameter.getdefaultvalueconstantname-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns string on success or <strong><code>NULL</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-reflectionparameter.getdefaultvalueconstantname-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-6463">
<p><strong>Example #1 Getting default values' constant names of function parameters</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">function </span><span style="color: #0000BB">foo</span><span style="color: #007700">(</span><span style="color: #0000BB">$test</span><span style="color: #007700">, </span><span style="color: #0000BB">$bar </span><span style="color: #007700">= </span><span style="color: #0000BB">PHP_INT_MIN</span><span style="color: #007700">)<br />{<br /> echo </span><span style="color: #0000BB">$test </span><span style="color: #007700">. </span><span style="color: #0000BB">$bar</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">$function </span><span style="color: #007700">= new </span><span style="color: #0000BB">ReflectionFunction</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo'</span><span style="color: #007700">);<br /><br />foreach (</span><span style="color: #0000BB">$function</span><span style="color: #007700">-></span><span style="color: #0000BB">getParameters</span><span style="color: #007700">() as </span><span style="color: #0000BB">$param</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">'Name: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">$param</span><span style="color: #007700">-></span><span style="color: #0000BB">getName</span><span style="color: #007700">() . </span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br /> if (</span><span style="color: #0000BB">$param</span><span style="color: #007700">-></span><span style="color: #0000BB">isOptional</span><span style="color: #007700">()) {<br /> echo </span><span style="color: #DD0000">'Default value: ' </span><span style="color: #007700">. </span><span style="color: #0000BB">$param</span><span style="color: #007700">-></span><span style="color: #0000BB">getDefaultValueConstantName</span><span style="color: #007700">() . </span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br /> }<br /> echo </span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Name: test
Name: bar
Default value: PHP_INT_MIN
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-reflectionparameter.getdefaultvalueconstantname-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
Due to implementation details, it is not possible to get the default value
of built-in functions or methods of built-in classes. Trying to do this will
result a <a href="class.reflectionexception.html" class="classname">ReflectionException</a> being thrown.
</p>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-reflectionparameter.getdefaultvalueconstantname-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="methodname"><a href="reflectionparameter.isoptional.html" class="methodname" rel="rdfs-seeAlso">ReflectionParameter::isOptional()</a> - Checks if optional</span></li>
<li class="member"><span class="methodname"><a href="reflectionparameter.isdefaultvalueconstant.html" class="methodname" rel="rdfs-seeAlso">ReflectionParameter::isDefaultValueConstant()</a> - Returns whether the default value of this parameter is a constant</span></li>
<li class="member"><span class="methodname"><a href="reflectionparameter.getdefaultvalue.html" class="methodname" rel="rdfs-seeAlso">ReflectionParameter::getDefaultValue()</a> - Gets default parameter value</span></li>
</ul>
</p>
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