<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Anonymous classes</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="language.oop5.traits.html">Traits</a></div>
<div class="next" style="text-align: right; float: right;"><a href="language.oop5.overloading.html">Overloading</a></div>
<div class="up"><a href="language.oop5.html">Classes and Objects</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="language.oop5.anonymous" class="sect1">
<h2 class="title">Anonymous classes</h2>
<p class="para">
Support for anonymous classes was added in PHP 7. Anonymous classes are
useful when simple, one-off objects need to be created.
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">// Pre PHP 7 code<br /></span><span style="color: #007700">class </span><span style="color: #0000BB">Logger<br /></span><span style="color: #007700">{<br /> public function </span><span style="color: #0000BB">log</span><span style="color: #007700">(</span><span style="color: #0000BB">$msg</span><span style="color: #007700">)<br /> {<br /> echo </span><span style="color: #0000BB">$msg</span><span style="color: #007700">;<br /> }<br />}<br /><br /></span><span style="color: #0000BB">$util</span><span style="color: #007700">-></span><span style="color: #0000BB">setLogger</span><span style="color: #007700">(new </span><span style="color: #0000BB">Logger</span><span style="color: #007700">());<br /><br /></span><span style="color: #FF8000">// PHP 7+ code<br /></span><span style="color: #0000BB">$util</span><span style="color: #007700">-></span><span style="color: #0000BB">setLogger</span><span style="color: #007700">(new class {<br /> public function </span><span style="color: #0000BB">log</span><span style="color: #007700">(</span><span style="color: #0000BB">$msg</span><span style="color: #007700">)<br /> {<br /> echo </span><span style="color: #0000BB">$msg</span><span style="color: #007700">;<br /> }<br />});</span>
</span>
</code></div>
</div>
</div>
<p class="para">
They can pass arguments through to their constructors, extend other classes,
implement interfaces, and use traits just like a normal class can:
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">class </span><span style="color: #0000BB">SomeClass </span><span style="color: #007700">{}<br />interface </span><span style="color: #0000BB">SomeInterface </span><span style="color: #007700">{}<br />trait </span><span style="color: #0000BB">SomeTrait </span><span style="color: #007700">{}<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(new class(</span><span style="color: #0000BB">10</span><span style="color: #007700">) extends </span><span style="color: #0000BB">SomeClass </span><span style="color: #007700">implements </span><span style="color: #0000BB">SomeInterface </span><span style="color: #007700">{<br /> private </span><span style="color: #0000BB">$num</span><span style="color: #007700">;<br /><br /> public function </span><span style="color: #0000BB">__construct</span><span style="color: #007700">(</span><span style="color: #0000BB">$num</span><span style="color: #007700">)<br /> {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">num </span><span style="color: #007700">= </span><span style="color: #0000BB">$num</span><span style="color: #007700">;<br /> }<br /><br /> use </span><span style="color: #0000BB">SomeTrait</span><span style="color: #007700">;<br />});</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
object(class@anonymous)#1 (1) {
["Command line code0x104c5b612":"class@anonymous":private]=>
int(10)
}
</pre></div>
</div>
</div>
<p class="para">
Nesting an anonymous class within another class does not give it access to
any private or protected methods or properties of that outer class. In order
to use the outer class' protected properties or methods, the anonymous class
can extend the outer class. To use the private properties of
the outer class in the anonymous class, they must be passed through its
constructor:
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">class </span><span style="color: #0000BB">Outer<br /></span><span style="color: #007700">{<br /> private </span><span style="color: #0000BB">$prop </span><span style="color: #007700">= </span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /> protected </span><span style="color: #0000BB">$prop2 </span><span style="color: #007700">= </span><span style="color: #0000BB">2</span><span style="color: #007700">;<br /><br /> protected function </span><span style="color: #0000BB">func1</span><span style="color: #007700">()<br /> {<br /> return </span><span style="color: #0000BB">3</span><span style="color: #007700">;<br /> }<br /><br /> public function </span><span style="color: #0000BB">func2</span><span style="color: #007700">()<br /> {<br /> return new class(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">prop</span><span style="color: #007700">) extends </span><span style="color: #0000BB">Outer </span><span style="color: #007700">{<br /> private </span><span style="color: #0000BB">$prop3</span><span style="color: #007700">;<br /><br /> public function </span><span style="color: #0000BB">__construct</span><span style="color: #007700">(</span><span style="color: #0000BB">$prop</span><span style="color: #007700">)<br /> {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">prop3 </span><span style="color: #007700">= </span><span style="color: #0000BB">$prop</span><span style="color: #007700">;<br /> }<br /><br /> public function </span><span style="color: #0000BB">func3</span><span style="color: #007700">()<br /> {<br /> return </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">prop2 </span><span style="color: #007700">+ </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">prop3 </span><span style="color: #007700">+ </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">func1</span><span style="color: #007700">();<br /> }<br /> };<br /> }<br />}<br /><br />echo (new </span><span style="color: #0000BB">Outer</span><span style="color: #007700">)-></span><span style="color: #0000BB">func2</span><span style="color: #007700">()-></span><span style="color: #0000BB">func3</span><span style="color: #007700">();</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
6
</pre></div>
</div>
</div>
<p class="para">
All objects created by the same anonymous class declaration are instances of
that very class.
</p>
<div class="informalexample">
<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">anonymous_class</span><span style="color: #007700">()<br />{<br /> return new class {};<br />}<br /><br />if (</span><span style="color: #0000BB">get_class</span><span style="color: #007700">(</span><span style="color: #0000BB">anonymous_class</span><span style="color: #007700">()) === </span><span style="color: #0000BB">get_class</span><span style="color: #007700">(</span><span style="color: #0000BB">anonymous_class</span><span style="color: #007700">())) {<br /> echo </span><span style="color: #DD0000">'same class'</span><span style="color: #007700">;<br />} else {<br /> echo </span><span style="color: #DD0000">'different class'</span><span style="color: #007700">;<br />}</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
same class
</pre></div>
</div>
</div>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
Note that anonymous classes are assigned a name by the engine, as
demonstrated in the following example. This name has to be regarded an
implementation detail, which should not be relied upon.
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">get_class</span><span style="color: #007700">(new class {});</span>
</span>
</code></div>
</div>
<p class="para">The above example will output
something similar to:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
class@anonymous/in/oNi1A0x7f8636ad2021
</pre></div>
</div>
</div>
</p></blockquote>
</div><hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="language.oop5.traits.html">Traits</a></div>
<div class="next" style="text-align: right; float: right;"><a href="language.oop5.overloading.html">Overloading</a></div>
<div class="up"><a href="language.oop5.html">Classes and Objects</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
