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</div><hr /><div id="function.substr" class="refentry">
<div class="refnamediv">
<h1 class="refname">substr</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">substr</span> — <span class="dc-title">Return part of a string</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.substr-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>substr</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$string</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$start</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$length</code></span>
] )</div>
<p class="para rdfs-comment">
Returns the portion of <em><code class="parameter">string</code></em> specified by the
<em><code class="parameter">start</code></em> and <em><code class="parameter">length</code></em> parameters.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.substr-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">string</code></em></span>
<dd>
<p class="para">
The input string. Must be one character or longer.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">start</code></em></span>
<dd>
<p class="para">
If <em><code class="parameter">start</code></em> is non-negative, the returned string
will start at the <em><code class="parameter">start</code></em>'th position in
<em><code class="parameter">string</code></em>, counting from zero. For instance,
in the string '<em>abcdef</em>', the character at
position <em>0</em> is '<em>a</em>', the
character at position <em>2</em> is
'<em>c</em>', and so forth.
</p>
<p class="para">
If <em><code class="parameter">start</code></em> is negative, the returned string
will start at the <em><code class="parameter">start</code></em>'th character
from the end of <em><code class="parameter">string</code></em>.
</p>
<p class="para">
If <em><code class="parameter">string</code></em> is less than or equal to
<em><code class="parameter">start</code></em> characters long, <strong><code>FALSE</code></strong> will be returned.
</p>
<p class="para">
<div class="example" id="example-4917">
<p><strong>Example #1 Using a negative <em><code class="parameter">start</code></em></strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "f"<br /></span><span style="color: #0000BB">$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, -</span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "ef"<br /></span><span style="color: #0000BB">$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, -</span><span style="color: #0000BB">3</span><span style="color: #007700">, </span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "d"<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">length</code></em></span>
<dd>
<p class="para">
If <em><code class="parameter">length</code></em> is given and is positive, the string
returned will contain at most <em><code class="parameter">length</code></em> characters
beginning from <em><code class="parameter">start</code></em> (depending on the length of
<em><code class="parameter">string</code></em>).
</p>
<p class="para">
If <em><code class="parameter">length</code></em> is given and is negative, then that many
characters will be omitted from the end of <em><code class="parameter">string</code></em>
(after the start position has been calculated when a
<em><code class="parameter">start</code></em> is negative). If
<em><code class="parameter">start</code></em> denotes the position of this truncation or
beyond, false will be returned.
</p>
<p class="para">
If <em><code class="parameter">length</code></em> is given and is <em>0</em>,
<strong><code>FALSE</code></strong> or <strong><code>NULL</code></strong> an empty string will be returned.
</p>
<p class="para">
If <em><code class="parameter">length</code></em> is omitted, the substring starting from
<em><code class="parameter">start</code></em> until the end of the string will be
returned.
</p>
<div class="example" id="example-4918">
<p><strong>Example #2 Using a negative <em><code class="parameter">length</code></em></strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "abcde"<br /></span><span style="color: #0000BB">$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "cde"<br /></span><span style="color: #0000BB">$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, </span><span style="color: #0000BB">4</span><span style="color: #007700">, -</span><span style="color: #0000BB">4</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns false<br /></span><span style="color: #0000BB">$rest </span><span style="color: #007700">= </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"abcdef"</span><span style="color: #007700">, -</span><span style="color: #0000BB">3</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// returns "de"<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.substr-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the extracted part of string; or <strong><code>FALSE</code></strong> on failure, or
an empty <em><code class="parameter">string</code></em>.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.substr-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>5.2.2 - 5.2.6</td>
<td>
If the <em><code class="parameter">start</code></em> parameter indicates the position of
a negative truncation or beyond, false is returned. Other versions get
the string from start.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.substr-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4919">
<p><strong>Example #3 Basic <span class="function"><strong>substr()</strong></span> usage</strong></p>
<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">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'abcdef'</span><span style="color: #007700">, </span><span style="color: #0000BB">1</span><span style="color: #007700">); </span><span style="color: #FF8000">// bcdef<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'abcdef'</span><span style="color: #007700">, </span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">3</span><span style="color: #007700">); </span><span style="color: #FF8000">// bcd<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'abcdef'</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">4</span><span style="color: #007700">); </span><span style="color: #FF8000">// abcd<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'abcdef'</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">8</span><span style="color: #007700">); </span><span style="color: #FF8000">// abcdef<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'abcdef'</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">); </span><span style="color: #FF8000">// f<br /><br />// Accessing single characters in a string<br />// can also be achieved using "square brackets"<br /></span><span style="color: #0000BB">$string </span><span style="color: #007700">= </span><span style="color: #DD0000">'abcdef'</span><span style="color: #007700">;<br />echo </span><span style="color: #0000BB">$string</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]; </span><span style="color: #FF8000">// a<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">$string</span><span style="color: #007700">[</span><span style="color: #0000BB">3</span><span style="color: #007700">]; </span><span style="color: #FF8000">// d<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">$string</span><span style="color: #007700">[</span><span style="color: #0000BB">strlen</span><span style="color: #007700">(</span><span style="color: #0000BB">$string</span><span style="color: #007700">)-</span><span style="color: #0000BB">1</span><span style="color: #007700">]; </span><span style="color: #FF8000">// f<br /><br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-4920">
<p><strong>Example #4 <span class="function"><strong>substr()</strong></span> casting behaviour</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">class </span><span style="color: #0000BB">apple </span><span style="color: #007700">{<br /> public function </span><span style="color: #0000BB">__toString</span><span style="color: #007700">() {<br /> return </span><span style="color: #DD0000">"green"</span><span style="color: #007700">;<br /> }<br />}<br /><br />echo </span><span style="color: #DD0000">"1) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">"pear"</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"2) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #0000BB">54321</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"3) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(new </span><span style="color: #0000BB">apple</span><span style="color: #007700">(), </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"4) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #0000BB">true</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">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"5) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #0000BB">false</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">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"6) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">""</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">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"7) "</span><span style="color: #007700">.</span><span style="color: #0000BB">var_export</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #0000BB">1.2e3</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">4</span><span style="color: #007700">), </span><span style="color: #0000BB">true</span><span style="color: #007700">).</span><span style="color: #0000BB">PHP_EOL</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
1) 'pe'
2) '54'
3) 'gr'
4) '1'
5) false
6) false
7) '1200'
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 errors" id="refsect1-function.substr-errors">
<h3 class="title">Errors/Exceptions</h3>
<p class="para">
Returns <strong><code>FALSE</code></strong> on error.
<div class="example" id="example-4921">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">substr</span><span style="color: #007700">(</span><span style="color: #DD0000">'a'</span><span style="color: #007700">, </span><span style="color: #0000BB">1</span><span style="color: #007700">)); </span><span style="color: #FF8000">// bool(false)<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.substr-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.strrchr.html" class="function" rel="rdfs-seeAlso">strrchr()</a> - Find the last occurrence of a character in a string</span></li>
<li class="member"> <span class="function"><a href="function.substr-replace.html" class="function" rel="rdfs-seeAlso">substr_replace()</a> - Replace text within a portion of a string</span></li>
<li class="member"> <span class="function"><a href="function.preg-match.html" class="function" rel="rdfs-seeAlso">preg_match()</a> - Perform a regular expression match</span></li>
<li class="member"> <span class="function"><a href="function.trim.html" class="function" rel="rdfs-seeAlso">trim()</a> - Strip whitespace (or other characters) from the beginning and end of a string</span></li>
<li class="member"> <span class="function"><a href="function.mb-substr.html" class="function" rel="rdfs-seeAlso">mb_substr()</a> - Get part of string</span></li>
<li class="member"> <span class="function"><a href="function.wordwrap.html" class="function" rel="rdfs-seeAlso">wordwrap()</a> - Wraps a string to a given number of characters</span></li>
<li class="member"><a href="language.types.string.html#language.types.string.substr" class="link">String access and modification by character</a></li>
</ul>
</p>
</div>
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