control-structures.foreach.html

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    <i>$value</i> with &amp;. This will assign
    <a href="language.references.html" class="link">reference</a> instead of copying
    the value.
    <div class="informalexample">
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$arr&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">4</span><span style="color: #007700">);<br />foreach&nbsp;(</span><span style="color: #0000BB">$arr&nbsp;</span><span style="color: #007700">as&nbsp;&amp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$value&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$value&nbsp;</span><span style="color: #007700">*&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">;<br />}<br /></span><span style="color: #FF8000">//&nbsp;$arr&nbsp;is&nbsp;now&nbsp;array(2,&nbsp;4,&nbsp;6,&nbsp;8)<br /></span><span style="color: #007700">unset(</span><span style="color: #0000BB">$value</span><span style="color: #007700">);&nbsp;</span><span style="color: #FF8000">//&nbsp;break&nbsp;the&nbsp;reference&nbsp;with&nbsp;the&nbsp;last&nbsp;element<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

    </div>
    This is possible only if iterated array can be referenced (i.e. is
    variable).
   </p>
   <div class="warning"><b class="warning">Warning</b>
    <p class="para">
     Reference of a <i>$value</i> and the last array element
     remain even after the <i>foreach</i> loop. It is recommended
     to destroy it by <a href="function.unset.html" class="function">unset()</a>.
    </p>
   </div>
   <p class="para">
    <blockquote><p><b class="note">Note</b>: 
     
      <i>foreach</i> does not support the ability to
      suppress error messages using &#039;@&#039;.
     <br />
    </p></blockquote>
   </p>
   <p class="para">
    You may have noticed that the following are functionally
    identical:
    <div class="informalexample">
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$arr&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #DD0000">"one"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"two"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"three"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">reset</span><span style="color: #007700">(</span><span style="color: #0000BB">$arr</span><span style="color: #007700">);<br />while&nbsp;(list(,&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;=&nbsp;</span><span style="color: #0000BB">each</span><span style="color: #007700">(</span><span style="color: #0000BB">$arr</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Value:&nbsp;$value&lt;br&nbsp;/&gt;\n"</span><span style="color: #007700">;<br />}<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$arr&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Value:&nbsp;$value&lt;br&nbsp;/&gt;\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

    </div>
    The following are also functionally identical:
    <div class="informalexample">
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$arr&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #DD0000">"one"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"two"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"three"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">reset</span><span style="color: #007700">(</span><span style="color: #0000BB">$arr</span><span style="color: #007700">);<br />while&nbsp;(list(</span><span style="color: #0000BB">$key</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$value</span><span style="color: #007700">)&nbsp;=&nbsp;</span><span style="color: #0000BB">each</span><span style="color: #007700">(</span><span style="color: #0000BB">$arr</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Key:&nbsp;$key;&nbsp;Value:&nbsp;$value&lt;br&nbsp;/&gt;\n"</span><span style="color: #007700">;<br />}<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$arr&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;echo&nbsp;</span><span style="color: #DD0000">"Key:&nbsp;$key;&nbsp;Value:&nbsp;$value&lt;br&nbsp;/&gt;\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

    </div>
   </p>
   <p class="para">
    Some more examples to demonstrate usages:
    <div class="informalexample">
     <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">/*&nbsp;foreach&nbsp;example&nbsp;1:&nbsp;value&nbsp;only&nbsp;*/<br /><br /></span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">17</span><span style="color: #007700">);<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$v</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Current&nbsp;value&nbsp;of&nbsp;\$a:&nbsp;$v.\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;foreach&nbsp;example&nbsp;2:&nbsp;value&nbsp;(with&nbsp;its&nbsp;manual&nbsp;access&nbsp;notation&nbsp;printed&nbsp;for&nbsp;illustration)&nbsp;*/<br /><br /></span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&nbsp;array(</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">17</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$i&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">;&nbsp;</span><span style="color: #FF8000">/*&nbsp;for&nbsp;illustrative&nbsp;purposes&nbsp;only&nbsp;*/<br /><br /></span><span style="color: #007700">foreach&nbsp;(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$v</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"\$a[$i]&nbsp;=&gt;&nbsp;$v.\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$i</span><span style="color: #007700">++;<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;foreach&nbsp;example&nbsp;3:&nbsp;key&nbsp;and&nbsp;value&nbsp;*/<br /><br /></span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">"one"&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">"two"&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">"three"&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">"seventeen"&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">17<br /></span><span style="color: #007700">);<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$k&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">$v</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"\$a[$k]&nbsp;=&gt;&nbsp;$v.\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;foreach&nbsp;example&nbsp;4:&nbsp;multi-dimensional&nbsp;arrays&nbsp;*/<br /></span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">=&nbsp;array();<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">][</span><span style="color: #0000BB">0</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #DD0000">"a"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">][</span><span style="color: #0000BB">1</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #DD0000">"b"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">][</span><span style="color: #0000BB">0</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #DD0000">"y"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">][</span><span style="color: #0000BB">1</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #DD0000">"z"</span><span style="color: #007700">;<br /><br />foreach&nbsp;(</span><span style="color: #0000BB">$a&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$v1</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;foreach&nbsp;(</span><span style="color: #0000BB">$v1&nbsp;</span><span style="color: #007700">as&nbsp;</span><span style="color: #0000BB">$v2</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"$v2\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;foreach&nbsp;example&nbsp;5:&nbsp;dynamic&nbsp;arrays&nbsp;*/<br /><br /></span><span style="color: #007700">foreach&nbsp;(array(</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">4</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">5</span><span style="color: #007700">)&nbsp;as&nbsp;</span><span style="color: #0000BB">$v</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"$v\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
     </div>

    </div>
   </p>
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