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<title>Finds out whether a variable is a boolean</title>
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<h1 class="refname">is_bool</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">is_bool</span> — <span class="dc-title">
Finds out whether a variable is a boolean
</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.is-bool-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>is_bool</strong></span>
( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$var</code></span>
)</div>
<p class="para rdfs-comment">
Finds whether the given variable is a boolean.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.is-bool-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">var</code></em></span>
<dd>
<p class="para">
The variable being evaluated.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.is-bool-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> if <em><code class="parameter">var</code></em> is a <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span>,
<strong><code>FALSE</code></strong> otherwise.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.is-bool-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-5257">
<p><strong>Example #1 <span class="function"><strong>is_bool()</strong></span> examples</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$a </span><span style="color: #007700">= </span><span style="color: #0000BB">false</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$b </span><span style="color: #007700">= </span><span style="color: #0000BB">0</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">// Since $a is a boolean, it will return true<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">is_bool</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">) === </span><span style="color: #0000BB">true</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"Yes, this is a boolean"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">// Since $b is not a boolean, it will return false<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">is_bool</span><span style="color: #007700">(</span><span style="color: #0000BB">$b</span><span style="color: #007700">) === </span><span style="color: #0000BB">false</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"No, this is not a boolean"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.is-bool-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.is-float.html" class="function" rel="rdfs-seeAlso">is_float()</a> - Finds whether the type of a variable is float</span></li>
<li class="member"> <span class="function"><a href="function.is-int.html" class="function" rel="rdfs-seeAlso">is_int()</a> - Find whether the type of a variable is integer</span></li>
<li class="member"> <span class="function"><a href="function.is-string.html" class="function" rel="rdfs-seeAlso">is_string()</a> - Find whether the type of a variable is string</span></li>
<li class="member"> <span class="function"><a href="function.is-object.html" class="function" rel="rdfs-seeAlso">is_object()</a> - Finds whether a variable is an object</span></li>
<li class="member"> <span class="function"><a href="function.is-array.html" class="function" rel="rdfs-seeAlso">is_array()</a> - Finds whether a variable is an array</span></li>
</ul>
</p>
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