doc-en/language/control-structures/continue.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->

<sect1 xml:id="control-structures.continue" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
 <title>continue</title>
 <?phpdoc print-version-for="continue"?>
 <simpara>
  <literal>continue</literal> is used within looping structures to
  skip the rest of the current loop iteration and continue execution
  at the condition evaluation and then the beginning of the next iteration.
 </simpara>
 <note>
  <simpara>
   In PHP the
   <link linkend="control-structures.switch">switch</link> statement is
   considered a looping structure for the purposes of
   <literal>continue</literal>. <literal>continue</literal> behaves like
   <literal>break</literal> (when no arguments are passed) but will
   raise a warning as this is likely to be a mistake. If a 
   <literal>switch</literal> is inside a loop,
   <literal>continue 2</literal> will continue with the next iteration
   of the outer loop.
  </simpara>
 </note>
 <simpara>
  <literal>continue</literal> accepts an optional numeric argument
  which tells it how many levels of enclosing loops it should skip
  to the end of. The default value is <literal>1</literal>, thus skipping
  to the end of the current loop.
 </simpara>
 <para>
  <informalexample>
   <programlisting role="php">
<![CDATA[
<?php
$arr = ['zero', 'one', 'two', 'three', 'four', 'five', 'six'];
foreach ($arr as $key => $value) {
    if (0 === ($key % 2)) { // skip members with even key
        continue;
    }
    echo $value . "\n";
}
?>
]]>
   </programlisting>
   &examples.outputs;
   <screen>
<![CDATA[
one
three
five
]]>
   </screen>
   <programlisting role="php">
<![CDATA[
<?php
$i = 0;
while ($i++ < 5) {
    echo "Outer\n";
    while (1) {
        echo "Middle\n";
        while (1) {
            echo "Inner\n";
            continue 3;
        }
        echo "This never gets output.\n";
    }
    echo "Neither does this.\n";
}
?>
]]>
   </programlisting>
   &examples.outputs;
   <screen>
<![CDATA[
Outer
Middle
Inner
Outer
Middle
Inner
Outer
Middle
Inner
Outer
Middle
Inner
Outer
Middle
Inner
]]>
   </screen>
  </informalexample>
 </para>
 <para>
  Omitting the semicolon after <literal>continue</literal> can lead to
  confusion. Here's an example of what you shouldn't do.
 </para>
 <para>
  <informalexample>
   <programlisting role="php">
<![CDATA[
<?php
for ($i = 0; $i < 5; ++$i) {
    if ($i == 2)
        continue
    print "$i\n";
}
?>
]]>
   </programlisting>
   <para>
    One can expect the result to be:
   </para>
   <screen>
<![CDATA[
0
1
3
4
]]>
   </screen>
  </informalexample>
 </para>
 <para>
  <table>
   <title>Changelog for <literal>continue</literal></title>
   <tgroup cols="2">
    <thead>
     <row>
      <entry>&Version;</entry>
      <entry>&Description;</entry>
     </row>
    </thead>
    <tbody>
     <row>
      <entry>7.3.0</entry>
      <entry>
       <literal>continue</literal> within a <literal>switch</literal> that is attempting to act like a <literal>break</literal> statement for the 
       <literal>switch</literal> will trigger an <constant>E_WARNING</constant>.
      </entry>
     </row>
    </tbody>
   </tgroup>
  </table>
 </para>
</sect1>

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