Sophie

Sophie

distrib > Mageia > 7 > x86_64 > by-pkgid > 2b917e0437961edec048f1d15e2d7449 > files > 9387

php-manual-en-7.2.11-1.mga7.noarch.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>Exceptions</title>

 </head>
 <body><div class="manualnavbar" style="text-align: center;">
 <div class="prev" style="text-align: left; float: left;"><a href="language.errors.php7.html">Errors in PHP 7</a></div>
 <div class="next" style="text-align: right; float: right;"><a href="language.exceptions.extending.html">Extending Exceptions</a></div>
 <div class="up"><a href="langref.html">Language Reference</a></div>
 <div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="language.exceptions" class="chapter">
  <h1>Exceptions</h1>
<h2>Table of Contents</h2><ul class="chunklist chunklist_chapter"><li><a href="language.exceptions.extending.html">Extending Exceptions</a></li></ul>

   
  

  <div class="simplesect">
   <p class="para">
    PHP 5 has an exception model similar to that of other programming
    languages.  An exception can be <a href="language.exceptions.html" class="link"><em>throw</em></a>n, and caught (&quot;<a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a>ed&quot;) within
    PHP. Code may be surrounded in a <a href="language.exceptions.html" class="link"><em>try</em></a> block, to facilitate the catching
    of potential exceptions. Each <a href="language.exceptions.html" class="link"><em>try</em></a> must have at least one corresponding
    <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> or <a href="language.exceptions.html#language.exceptions.finally" class="link"><em>finally</em></a> block.
   </p>

   <p class="para">
    The thrown object must be an instance of the
    <a href="class.exception.html" class="classname">Exception</a> class or a subclass of
    <a href="class.exception.html" class="classname">Exception</a>. Trying to throw an object that is not
    will result in a PHP Fatal Error.
   </p>
  </div>

  <div class="simplesect">
   <h3 class="title"><em>catch</em></h3>
   <p class="para">
    Multiple <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> blocks can be used to catch different classes of
    exceptions. Normal execution (when no exception is thrown within the <a href="language.exceptions.html" class="link"><em>try</em></a>
    block) will continue after that last <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> block defined in sequence.
    Exceptions can be <a href="language.exceptions.html" class="link"><em>throw</em></a>n (or re-thrown) within a <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> block.
   </p>
   <p class="para">
    When an exception is thrown, code following the statement will not be
    executed, and PHP will attempt to find the first matching <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> block.
    If an exception is not caught, a PHP Fatal Error will be issued with an
    &quot;<em>Uncaught Exception ...</em>&quot; message, unless a handler has
    been defined with <span class="function"><a href="function.set-exception-handler.html" class="function">set_exception_handler()</a></span>.
   </p>
   <p class="para">
    In PHP 7.1 and later, a <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> block may specify multiple exceptions
    using the pipe (<em>|</em>) character. This is useful for when
    different exceptions from different class hierarchies are handled the
    same.
   </p>
  </div>

  <div class="simplesect">
   <h3 class="title"><em>finally</em></h3>
   <p class="para">
    In PHP 5.5 and later, a <a href="language.exceptions.html#language.exceptions.finally" class="link"><em>finally</em></a> block may also be specified after or
    instead of <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> blocks. Code within the <a href="language.exceptions.html#language.exceptions.finally" class="link"><em>finally</em></a> block will always be
    executed after the <a href="language.exceptions.html" class="link"><em>try</em></a> and <a href="language.exceptions.html#language.exceptions.catch" class="link"><em>catch</em></a> blocks, regardless of whether an
    exception has been thrown, and before normal execution resumes.
   </p>
  </div>

  <div class="simplesect">
   <h3 class="title">Notes</h3>

   <blockquote class="note"><p><strong class="note">Note</strong>: 
    <p class="para">
     Internal PHP functions mainly use
     <a href="errorfunc.configuration.html#ini.error-reporting" class="link">Error reporting</a>, only modern
     <a href="language.oop5.html" class="link">Object oriented</a>
     extensions use exceptions. However, errors can be simply translated to
     exceptions with <a href="class.errorexception.html" class="link">ErrorException</a>.
    </p>
   </p></blockquote>
   <div class="tip"><strong class="tip">Tip</strong>
    <p class="para">
     The <a href="intro.spl.html" class="link">Standard PHP Library (SPL)</a> provides
     a good number of <a href="spl.exceptions.html" class="link">built-in
     exceptions</a>.
    </p>
   </div>
  </div>

  <div class="simplesect">
   <h3 class="title">Examples</h3>

   <div class="example" id="example-280">
    <p><strong>Example #3 Throwing an Exception</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">$x</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;(!</span><span style="color: #0000BB">$x</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;throw&nbsp;new&nbsp;</span><span style="color: #0000BB">Exception</span><span style="color: #007700">(</span><span style="color: #DD0000">'Division&nbsp;by&nbsp;zero.'</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">/</span><span style="color: #0000BB">$x</span><span style="color: #007700">;<br />}<br /><br />try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">0</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">Exception&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Caught&nbsp;exception:&nbsp;'</span><span style="color: #007700">,&nbsp;&nbsp;</span><span style="color: #0000BB">$e</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">getMessage</span><span style="color: #007700">(),&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;Continue&nbsp;execution<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #DD0000">"Hello&nbsp;World\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</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>
0.2
Caught exception: Division by zero.
Hello World
</pre></div>
    </div>
   </div>
   <div class="example" id="example-281">
    <p><strong>Example #4 Exception handling with a <em>finally</em> block</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">$x</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;(!</span><span style="color: #0000BB">$x</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;throw&nbsp;new&nbsp;</span><span style="color: #0000BB">Exception</span><span style="color: #007700">(</span><span style="color: #DD0000">'Division&nbsp;by&nbsp;zero.'</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">/</span><span style="color: #0000BB">$x</span><span style="color: #007700">;<br />}<br /><br />try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">Exception&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Caught&nbsp;exception:&nbsp;'</span><span style="color: #007700">,&nbsp;&nbsp;</span><span style="color: #0000BB">$e</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">getMessage</span><span style="color: #007700">(),&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}&nbsp;</span><span style="color: #0000BB">finally&nbsp;</span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"First&nbsp;finally.\n"</span><span style="color: #007700">;<br />}<br /><br />try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">inverse</span><span style="color: #007700">(</span><span style="color: #0000BB">0</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">Exception&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Caught&nbsp;exception:&nbsp;'</span><span style="color: #007700">,&nbsp;&nbsp;</span><span style="color: #0000BB">$e</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">getMessage</span><span style="color: #007700">(),&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}&nbsp;</span><span style="color: #0000BB">finally&nbsp;</span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Second&nbsp;finally.\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">//&nbsp;Continue&nbsp;execution<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #DD0000">"Hello&nbsp;World\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</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>
0.2
First finally.
Caught exception: Division by zero.
Second finally.
Hello World
</pre></div>
    </div>
   </div>
   <div class="example" id="example-282">
    <p><strong>Example #5 Nested Exception</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">MyException&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">Exception&nbsp;</span><span style="color: #007700">{&nbsp;}<br /><br />class&nbsp;</span><span style="color: #0000BB">Test&nbsp;</span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">testing</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;throw&nbsp;new&nbsp;</span><span style="color: #0000BB">MyException</span><span style="color: #007700">(</span><span style="color: #DD0000">'foo!'</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">MyException&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">//&nbsp;rethrow&nbsp;it<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">throw&nbsp;</span><span style="color: #0000BB">$e</span><span style="color: #007700">;<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">Exception&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">$e</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">getMessage</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #0000BB">$foo&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">Test</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$foo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">testing</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">?&gt;</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>
string(4) &quot;foo!&quot;
</pre></div>
    </div>
   </div>
   <div class="example" id="example-283">
    <p><strong>Example #6 Multi catch exception handling</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">MyException&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">Exception&nbsp;</span><span style="color: #007700">{&nbsp;}<br /><br />class&nbsp;</span><span style="color: #0000BB">MyOtherException&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">Exception&nbsp;</span><span style="color: #007700">{&nbsp;}<br /><br />class&nbsp;</span><span style="color: #0000BB">Test&nbsp;</span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">testing</span><span style="color: #007700">()&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;try&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;throw&nbsp;new&nbsp;</span><span style="color: #0000BB">MyException</span><span style="color: #007700">();<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;catch&nbsp;(</span><span style="color: #0000BB">MyException&nbsp;</span><span style="color: #007700">|&nbsp;</span><span style="color: #0000BB">MyOtherException&nbsp;$e</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">get_class</span><span style="color: #007700">(</span><span style="color: #0000BB">$e</span><span style="color: #007700">));<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br /><br /></span><span style="color: #0000BB">$foo&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">Test</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$foo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">testing</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">?&gt;</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>
string(11) &quot;MyException&quot;
</pre></div>
    </div>
   </div>
  </div>

 </div>
<hr /><div class="manualnavbar" style="text-align: center;">
 <div class="prev" style="text-align: left; float: left;"><a href="language.errors.php7.html">Errors in PHP 7</a></div>
 <div class="next" style="text-align: right; float: right;"><a href="language.exceptions.extending.html">Extending Exceptions</a></div>
 <div class="up"><a href="langref.html">Language Reference</a></div>
 <div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>

Perl :: Catalyst :: PostgreSQL :: RPM Valid HTML 4.01 Transitional