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<title>The ArrayAccess interface</title>
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<h1 class="title">The ArrayAccess interface</h1>
<div class="partintro"><p class="verinfo">(PHP 5 >= 5.0.0)</p>
<div class="section" id="arrayaccess.intro">
<h2 class="title">Introduction</h2>
<p class="para">
Interface to provide accessing objects as arrays.
</p>
</div>
<div class="section" id="arrayaccess.synopsis">
<h2 class="title">Interface synopsis</h2>
<div class="classsynopsis">
<div class="ooclass"></div>
<div class="classsynopsisinfo">
<span class="ooclass">
<strong class="classname">ArrayAccess</strong>
</span>
{</div>
<div class="classsynopsisinfo classsynopsisinfo_comment">/* Methods */</div>
<div class="methodsynopsis dc-description">
<span class="modifier">abstract</span> <span class="modifier">public</span> <span class="type">boolean</span> <span class="methodname"><a href="arrayaccess.offsetexists.html" class="methodname">offsetExists</a></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">$offset</code></span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">abstract</span> <span class="modifier">public</span> <span class="type">mixed</span> <span class="methodname"><a href="arrayaccess.offsetget.html" class="methodname">offsetGet</a></span>
( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$offset</code></span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">abstract</span> <span class="modifier">public</span> <span class="type">void</span> <span class="methodname"><a href="arrayaccess.offsetset.html" class="methodname">offsetSet</a></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">$offset</code></span>
, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$value</code></span>
)</div>
<div class="methodsynopsis dc-description">
<span class="modifier">abstract</span> <span class="modifier">public</span> <span class="type">void</span> <span class="methodname"><a href="arrayaccess.offsetunset.html" class="methodname">offsetUnset</a></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">$offset</code></span>
)</div>
}</div>
</div>
<div class="section" id="arrayaccess.examples">
<div class="example" id="arrayaccess.example.basic">
<p><strong>Example #1 Basic usage</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">class </span><span style="color: #0000BB">obj </span><span style="color: #007700">implements </span><span style="color: #0000BB">arrayaccess </span><span style="color: #007700">{<br /> private </span><span style="color: #0000BB">$container </span><span style="color: #007700">= array();<br /> public function </span><span style="color: #0000BB">__construct</span><span style="color: #007700">() {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container </span><span style="color: #007700">= array(<br /> </span><span style="color: #DD0000">"one" </span><span style="color: #007700">=> </span><span style="color: #0000BB">1</span><span style="color: #007700">,<br /> </span><span style="color: #DD0000">"two" </span><span style="color: #007700">=> </span><span style="color: #0000BB">2</span><span style="color: #007700">,<br /> </span><span style="color: #DD0000">"three" </span><span style="color: #007700">=> </span><span style="color: #0000BB">3</span><span style="color: #007700">,<br /> );<br /> }<br /> public function </span><span style="color: #0000BB">offsetSet</span><span style="color: #007700">(</span><span style="color: #0000BB">$offset</span><span style="color: #007700">, </span><span style="color: #0000BB">$value</span><span style="color: #007700">) {<br /> if (</span><span style="color: #0000BB">is_null</span><span style="color: #007700">(</span><span style="color: #0000BB">$offset</span><span style="color: #007700">)) {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[] = </span><span style="color: #0000BB">$value</span><span style="color: #007700">;<br /> } else {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[</span><span style="color: #0000BB">$offset</span><span style="color: #007700">] = </span><span style="color: #0000BB">$value</span><span style="color: #007700">;<br /> }<br /> }<br /> public function </span><span style="color: #0000BB">offsetExists</span><span style="color: #007700">(</span><span style="color: #0000BB">$offset</span><span style="color: #007700">) {<br /> return isset(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[</span><span style="color: #0000BB">$offset</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">$offset</span><span style="color: #007700">) {<br /> unset(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[</span><span style="color: #0000BB">$offset</span><span style="color: #007700">]);<br /> }<br /> public function </span><span style="color: #0000BB">offsetGet</span><span style="color: #007700">(</span><span style="color: #0000BB">$offset</span><span style="color: #007700">) {<br /> return isset(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[</span><span style="color: #0000BB">$offset</span><span style="color: #007700">]) ? </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">container</span><span style="color: #007700">[</span><span style="color: #0000BB">$offset</span><span style="color: #007700">] : </span><span style="color: #0000BB">null</span><span style="color: #007700">;<br /> }<br />}<br /><br /></span><span style="color: #0000BB">$obj </span><span style="color: #007700">= new </span><span style="color: #0000BB">obj</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(isset(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">]));<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">]);<br />unset(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">]);<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(isset(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">]));<br /></span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">] = </span><span style="color: #DD0000">"A value"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$obj</span><span style="color: #007700">[</span><span style="color: #DD0000">"two"</span><span style="color: #007700">]);<br /></span><span style="color: #0000BB">$obj</span><span style="color: #007700">[] = </span><span style="color: #DD0000">'Append 1'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$obj</span><span style="color: #007700">[] = </span><span style="color: #DD0000">'Append 2'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$obj</span><span style="color: #007700">[] = </span><span style="color: #DD0000">'Append 3'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$obj</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>
bool(true)
int(2)
bool(false)
string(7) "A value"
obj Object
(
[container:obj:private] => Array
(
[one] => 1
[three] => 3
[two] => A value
[0] => Append 1
[1] => Append 2
[2] => Append 3
)
)
</pre></div>
</div>
</div>
</div>
</div>
<h2>Table of Contents</h2><ul class="chunklist chunklist_reference"><li><a href="arrayaccess.offsetexists.html">ArrayAccess::offsetExists</a> — Whether a offset exists</li><li><a href="arrayaccess.offsetget.html">ArrayAccess::offsetGet</a> — Offset to retrieve</li><li><a href="arrayaccess.offsetset.html">ArrayAccess::offsetSet</a> — Offset to set</li><li><a href="arrayaccess.offsetunset.html">ArrayAccess::offsetUnset</a> — Offset to unset</li></ul>
</div>
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