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<h1 class="refname">ArrayAccess::offsetExists</h1>
<p class="verinfo">(PHP 5 >= 5.0.0)</p><p class="refpurpose"><span class="refname">ArrayAccess::offsetExists</span> — <span class="dc-title">Whether a offset exists</span></p>
</div>
<div class="refsect1 description" id="refsect1-arrayaccess.offsetexists-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">abstract</span> <span class="modifier">public</span> <span class="type">boolean</span> <span class="methodname"><strong>ArrayAccess::offsetExists</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">$offset</code></span>
)</div>
<p class="para rdfs-comment">
Whether or not an offset exists.
</p>
<p class="para">
This method is executed when using <span class="function"><a href="function.isset.html" class="function">isset()</a></span> or
<span class="function"><a href="function.empty.html" class="function">empty()</a></span> on objects implementing <a href="class.arrayaccess.html" class="classname">ArrayAccess</a>.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
When using <span class="function"><a href="function.empty.html" class="function">empty()</a></span> <span class="function"><a href="arrayaccess.offsetget.html" class="function">ArrayAccess::offsetGet()</a></span> will
be called and checked if empty only if <span class="function"><strong>ArrayAccess::offsetExists()</strong></span>
returns <strong><code>TRUE</code></strong>.
</p>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-arrayaccess.offsetexists-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">offset</code></em></span>
<dd>
<p class="para">
An offset to check for.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-arrayaccess.offsetexists-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
The return value will be casted to <span class="type"><a href="language.types.boolean.html" class="type boolean">boolean</a></span> if non-boolean was returned.
</p>
</p></blockquote>
</div>
<div class="refsect1 examples" id="refsect1-arrayaccess.offsetexists-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-305">
<p><strong>Example #1 <span class="function"><strong>ArrayAccess::offsetExists()</strong></span> example</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">class </span><span style="color: #0000BB">obj </span><span style="color: #007700">implements </span><span style="color: #0000BB">arrayaccess </span><span style="color: #007700">{<br /> public function </span><span style="color: #0000BB">offsetSet</span><span style="color: #007700">(</span><span style="color: #0000BB">$offset</span><span style="color: #007700">, </span><span style="color: #0000BB">$value</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">__METHOD__</span><span style="color: #007700">);<br /> }<br /> public function </span><span style="color: #0000BB">offsetExists</span><span style="color: #007700">(</span><span style="color: #0000BB">$var</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">__METHOD__</span><span style="color: #007700">);<br /> if (</span><span style="color: #0000BB">$var </span><span style="color: #007700">== </span><span style="color: #DD0000">"foobar"</span><span style="color: #007700">) {<br /> return </span><span style="color: #0000BB">true</span><span style="color: #007700">;<br /> }<br /> return </span><span style="color: #0000BB">false</span><span style="color: #007700">;<br /> }<br /> public function </span><span style="color: #0000BB">offsetUnset</span><span style="color: #007700">(</span><span style="color: #0000BB">$var</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">__METHOD__</span><span style="color: #007700">);<br /> }<br /> public function </span><span style="color: #0000BB">offsetGet</span><span style="color: #007700">(</span><span style="color: #0000BB">$var</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">__METHOD__</span><span style="color: #007700">);<br /> return </span><span style="color: #DD0000">"value"</span><span style="color: #007700">;<br /> }<br />}<br /><br /></span><span style="color: #0000BB">$obj </span><span style="color: #007700">= new </span><span style="color: #0000BB">obj</span><span style="color: #007700">;<br /><br />echo </span><span style="color: #DD0000">"Runs obj::offsetExists()\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(isset(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"foobar"</span><span style="color: #007700">]));<br /><br />echo </span><span style="color: #DD0000">"\nRuns obj::offsetExists() and obj::offsetGet()\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(empty(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"foobar"</span><span style="color: #007700">]));<br /><br />echo </span><span style="color: #DD0000">"\nRuns obj::offsetExists(), *not* obj:offsetGet() as there is nothing to get\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(empty(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"foobaz"</span><span style="color: #007700">]));<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
Runs obj::offsetExists()
string(17) "obj::offsetExists"
bool(true)
Runs obj::offsetExists() and obj::offsetGet()
string(17) "obj::offsetExists"
string(14) "obj::offsetGet"
bool(false)
Runs obj::offsetExists(), *not* obj:offsetGet() as there is nothing to get
string(17) "obj::offsetExists"
bool(true)
</pre></div>
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