<?xml version="1.0" encoding="utf-8"?>
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<sect1 xml:id="control-structures.elseif" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
 <title><literal>elseif</literal>/<literal>else if</literal></title>
 <?phpdoc print-version-for="elseif"?>
 <para>
  <literal>elseif</literal>, as its name suggests, is a combination
  of <literal>if</literal> and <literal>else</literal>.  Like
  <literal>else</literal>, it extends an <literal>if</literal>
  statement to execute a different statement in case the original
  <literal>if</literal> expression evaluates to
  &false;.  However, unlike
  <literal>else</literal>, it will execute that alternative
  expression only if the <literal>elseif</literal> conditional
  expression evaluates to &true;.  For example, the
  following code would display <computeroutput>a is bigger than
  b</computeroutput>, <computeroutput>a equal to b</computeroutput>
  or <computeroutput>a is smaller than b</computeroutput>:
  <informalexample>
   <programlisting role="php">
<![CDATA[
<?php
if ($a > $b) {
    echo "a is bigger than b";
} elseif ($a == $b) {
    echo "a is equal to b";
} else {
    echo "a is smaller than b";
}
?>
]]>
   </programlisting>
  </informalexample>
 </para>
 <simpara>
  There may be several <literal>elseif</literal>s within the same
  <literal>if</literal> statement.  The first
  <literal>elseif</literal> expression (if any) that evaluates to
  &true; would be executed.  In PHP, you can also
  write 'else if' (in two words) and the behavior would be identical
  to the one of 'elseif' (in a single word).  The syntactic meaning
  is slightly different (if you're familiar with C, this is the same
  behavior) but the bottom line is that both would result in exactly
  the same behavior.
 </simpara>
 <simpara>
  The <literal>elseif</literal> statement is only executed if the
  preceding <literal>if</literal> expression and any preceding
  <literal>elseif</literal> expressions evaluated to
  &false;, and the current
  <literal>elseif</literal> expression evaluated to
  &true;.
 </simpara>
 <note>
  <simpara>
   Note that <literal>elseif</literal> and <literal>else if</literal>
   will only be considered exactly the same when using curly brackets
   as in the above example.  When using a colon to define your
   <literal>if</literal>/<literal>elseif</literal> conditions, you must
   not separate <literal>else if</literal> into two words, or PHP will
   fail with a parse error.
  </simpara>
 </note>
 <para>
  <informalexample>
   <programlisting role="php">
<![CDATA[
<?php

/* Incorrect Method: */
if($a > $b):
    echo $a." is greater than ".$b;
else if($a == $b): // Will not compile.
    echo "The above line causes a parse error.";
endif;


/* Correct Method: */
if($a > $b):
    echo $a." is greater than ".$b;
elseif($a == $b): // Note the combination of the words.
    echo $a." equals ".$b;
else:
    echo $a." is neither greater than or equal to ".$b;
endif;

?>
]]>
   </programlisting>
  </informalexample>
 </para>
</sect1>

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