downloads | documentation | faq | getting help | mailing lists | licenses | wiki | reporting bugs | php.net sites | links | conferences | my php.net

search for in the

Our source is open

The syntax highlighted source is automatically generated by PHP from the plaintext script. If you're interested in what's behind the several functions we used, you can always take a look at the source of the following files:

Of course, if you want to see the source of this page, we have it available. You can also browse the SVN repository for this website on svn.php.net.

Source of: /manual/en/language.oop5.iterations.php

<?php
include_once $_SERVER['DOCUMENT_ROOT'] . '/include/shared-manual.inc';
$TOC = array();
$PARENTS = array();
include_once dirname(__FILE__) ."/toc/language.oop5.inc";
$setup = array (
  'home' =>
  array (
    0 => 'index.php',
    1 => 'PHP Manual',
  ),
  'head' =>
  array (
    0 => 'UTF-8',
    1 => 'en',
  ),
  'this' =>
  array (
    0 => 'language.oop5.iterations.php',
    1 => 'Object Iteration',
  ),
  'up' =>
  array (
    0 => 'language.oop5.php',
    1 => 'Classes and Objects',
  ),
  'prev' =>
  array (
    0 => 'language.oop5.overloading.php',
    1 => 'Overloading',
  ),
  'next' =>
  array (
    0 => 'language.oop5.patterns.php',
    1 => 'Patterns',
  ),
);
$setup["toc"] = $TOC;
$setup["parents"] = $PARENTS;
manual_setup($setup);

manual_header();
?>
<div id="language.oop5.iterations" class="sect1">
  <h2 class="title">Object Iteration</h2>
  <p class="para">

   PHP 5 provides a way for objects to be defined so it is possible to iterate
   through a list of items, with, for example a <a href="control-structures.foreach.php" class="link">foreach</a> statement. By default,
   all <a href="language.oop5.visibility.php" class="link">visible</a> properties will be used
   for the iteration.

  </p>

  <div class="example">
   <p><b>Example #1 Simple Object Iteration</b></p>
   <div class="example-contents programlisting">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">MyClass<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;</span><span style="color: #0000BB">$var1&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'value&nbsp;1'</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;</span><span style="color: #0000BB">$var2&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'value&nbsp;2'</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;</span><span style="color: #0000BB">$var3&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'value&nbsp;3'</span><span style="color: #007700">;<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;protected&nbsp;</span><span style="color: #0000BB">$protected&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'protected&nbsp;var'</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$private&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'private&nbsp;var'</span><span style="color: #007700">;<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;function&nbsp;</span><span style="color: #0000BB">iterateVisible</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"MyClass::iterateVisible:\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;foreach(</span><span style="color: #0000BB">$this&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$key&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;print&nbsp;</span><span style="color: #DD0000">"</span><span style="color: #0000BB">$key</span><span style="color: #DD0000">&nbsp;=&gt;&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #0000BB">$class&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">MyClass</span><span style="color: #007700">();<br /><br />foreach(</span><span style="color: #0000BB">$class&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$key&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;print&nbsp;</span><span style="color: #DD0000">"</span><span style="color: #0000BB">$key</span><span style="color: #DD0000">&nbsp;=&gt;&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<br />echo&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /><br /><br /></span><span style="color: #0000BB">$class</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">iterateVisible</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
   </div>

   <div class="example-contents para"><p>The above example will output:</p></div>
   <div class="example-contents screen">
<div class="cdata"><pre>
var1 =&gt; value 1
var2 =&gt; value 2
var3 =&gt; value 3

MyClass::iterateVisible:
var1 =&gt; value 1
var2 =&gt; value 2
var3 =&gt; value 3
protected =&gt; protected var
private =&gt; private var
</pre></div>
   </div>

  </div>

 <p class="para">
  As the output shows, the <a href="control-structures.foreach.php" class="link">foreach</a> iterated through all
  <a href="language.oop5.visibility.php" class="link">visible</a> variables that can be
  accessed. To take it a step further you can implement one
  of PHP 5&#039;s internal <a href="language.oop5.interfaces.php" class="link">interface</a> named
  <var class="varname">Iterator</var>. This allows the object to decide what and how
  the object will be iterated.
 </p>

  <div class="example">
   <p><b>Example #2 Object Iteration implementing Iterator</b></p>
   <div class="example-contents programlisting">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">MyIterator&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">Iterator<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;</span><span style="color: #0000BB">$var&nbsp;</span><span style="color: #007700">=&nbsp;array();<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">__construct</span><span style="color: #007700">(</span><span style="color: #0000BB">$array</span><span style="color: #007700">)<br />&nbsp;&nbsp;&nbsp;&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;(</span><span style="color: #0000BB">is_array</span><span style="color: #007700">(</span><span style="color: #0000BB">$array</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">var&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$array</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">rewind</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"rewinding\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">reset</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">var</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">current</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$var&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">current</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">var</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"current:&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">key</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$var&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">key</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">var</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"key:&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">next</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$var&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">next</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">var</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"next:&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">valid</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$var&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">current</span><span style="color: #007700">()&nbsp;!==&nbsp;</span><span style="color: #0000BB">false</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"valid:&nbsp;</span><span style="color: #007700">{</span><span style="color: #0000BB">$var</span><span style="color: #007700">}</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">$var</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #0000BB">$values&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #0000BB">1</span><span style="color: #007700">,</span><span style="color: #0000BB">2</span><span style="color: #007700">,</span><span style="color: #0000BB">3</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$it&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">MyIterator</span><span style="color: #007700">(</span><span style="color: #0000BB">$values</span><span style="color: #007700">);<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$it&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$b</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;print&nbsp;</span><span style="color: #DD0000">"</span><span style="color: #0000BB">$a</span><span style="color: #DD0000">:&nbsp;</span><span style="color: #0000BB">$b</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
   </div>

   <div class="example-contents para"><p>The above example will output:</p></div>
   <div class="example-contents screen">
<div class="cdata"><pre>
rewinding
current: 1
valid: 1
current: 1
key: 0
0: 1
next: 2
current: 2
valid: 1
current: 2
key: 1
1: 2
next: 3
current: 3
valid: 1
current: 3
key: 2
2: 3
next:
current:
valid:
</pre></div>
   </div>

  </div>

  <p class="para">
   You can also define your class so that it doesn&#039;t have to define
   all the <var class="varname">Iterator</var> functions by simply implementing
   the PHP 5 <var class="varname">IteratorAggregate</var> interface.
  </p>

  <div class="example">
   <p><b>Example #3 Object Iteration implementing IteratorAggregate</b></p>
   <div class="example-contents programlisting">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">MyCollection&nbsp;</span><span style="color: #007700">implements&nbsp;</span><span style="color: #0000BB">IteratorAggregate<br /></span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;</span><span style="color: #0000BB">$items&nbsp;</span><span style="color: #007700">=&nbsp;array();<br />&nbsp;&nbsp;&nbsp;&nbsp;private&nbsp;</span><span style="color: #0000BB">$count&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">;<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">//&nbsp;Required&nbsp;definition&nbsp;of&nbsp;interface&nbsp;IteratorAggregate<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">public&nbsp;function&nbsp;</span><span style="color: #0000BB">getIterator</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;new&nbsp;</span><span style="color: #0000BB">MyIterator</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">items</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br /><br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">add</span><span style="color: #007700">(</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">items</span><span style="color: #007700">[</span><span style="color: #0000BB">$this</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">count</span><span style="color: #007700">++]&nbsp;=&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #0000BB">$coll&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">MyCollection</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">$coll</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">add</span><span style="color: #007700">(</span><span style="color: #DD0000">'value&nbsp;1'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$coll</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">add</span><span style="color: #007700">(</span><span style="color: #DD0000">'value&nbsp;2'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$coll</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">add</span><span style="color: #007700">(</span><span style="color: #DD0000">'value&nbsp;3'</span><span style="color: #007700">);<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$coll&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$key&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$val</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"key/value:&nbsp;[</span><span style="color: #0000BB">$key</span><span style="color: #DD0000">&nbsp;-&gt;&nbsp;</span><span style="color: #0000BB">$val</span><span style="color: #DD0000">]\n\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
   </div>

   <div class="example-contents para"><p>The above example will output:</p></div> 
   <div class="example-contents screen">
<div class="cdata"><pre>
rewinding
current: value 1
valid: 1
current: value 1
key: 0
key/value: [0 -&gt; value 1]

next: value 2
current: value 2
valid: 1
current: value 2
key: 1
key/value: [1 -&gt; value 2]

next: value 3
current: value 3
valid: 1
current: value 3
key: 2
key/value: [2 -&gt; value 3]

next:
current:
valid:
</pre></div>
   </div>

  </div>

  <blockquote><p><b class="note">Note</b>:
  
    For more examples of iterators, see the
    <a href="spl.iterators.php" class="link">SPL Extension</a>.
   <br />
  </p></blockquote>

 </div><?php manual_footer(); ?>
 
show source | credits | sitemap | contact | advertising | mirror sites