sigmasternchen/php-doc-en
1
0
Fork 0
mirror of https://github.com/sigmasternchen/php-doc-en synced 2025-03-15 16:38:54 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Improve goto description and add a couple of examples. Remove the

Browse source 
warning because I think it is better to simply describe that
restriction up front.


git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@282476 c90b9560-bf6c-de11-be94-00142212c4b1
This commit is contained in:
Rasmus Lerdorf 2009-06-20 18:07:12 +00:00
parent 7d553b8809
commit 6676521c23
1 changed files with 58 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

66
language/control-structures/goto.xml
View file

@ -1,5 +1,5 @@
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision: 1.3 $ -->
<!-- $Revision: 1.4 $ -->
<sect1 xml:id="control-structures.goto" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<title><literal>goto</literal></title>
@ -7,7 +7,13 @@
The <literal>goto</literal> operator can be used to jump to another
section in the program. The target point is specified by a label
followed by a colon, and the instruction is given as
<literal>goto</literal> followed by the desired target label.
<literal>goto</literal> followed by the desired target label. This
is not a full unrestricted <literal>goto</literal>. The target
label must be within the same context, meaning that you cannot jump
out of a function or method, nor can you jump into one. You also
cannot jump into any sort of loop or switch structure. You may jump
out of these, and a common use is to use a <literal>goto</literal>
in place of a multi-level <literal>break</literal>.
</para>
<para>
<example>
@ -27,6 +33,56 @@ echo 'Bar';
<screen>
<![CDATA[
Bar
]]>
</screen>
</example>
</para>
<para>
<example>
<title><literal>goto</literal> loop example</title>
<programlisting role="php">
<![CDATA[
<?php
for($i=0,$j=50; $i<100; $i++) {
while($j--) {
if($j==17) goto end;
}
}
echo "i = $i";
end:
echo 'j hit 17';
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
j hit 17
]]>
</screen>
</example>
</para>
<para>
<example>
<title>This will not work</title>
<programlisting role="php">
<![CDATA[
<?php
goto loop;
for($i=0,$j=50; $i<100; $i++) {
while($j--) {
loop:
}
}
echo "$i = $i";
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
Fatal error: 'goto' into loop or switch statement is disallowed in
script on line 2
]]>
</screen>
</example>
@ -36,12 +92,6 @@ Bar
The <literal>goto</literal> operator is available as of PHP 5.3.
</para>
</note>
<warning>
<para>
It is not allowed to jump into a loop or switch statement. A fatal
error is issued in such cases.
</para>
</warning>
<para>
<mediaobject>
<imageobject>