include_once
since label executes all the time even if you don't use goto label;
<?php
if (false)
goto label
label :
echo "label triggered";
?>
Will output: label triggered
I use labels like this
<?php
...some code...
if (false) {
label1 :
echo "label 1 triggered";
}
if (false) {
label2 :
echo "label 2 triggered";
}
if (false) {
label3 :
echo "label 3 triggered";
}
?>
It will never output unless you use "goto <label>".
goto
Операторът goto може да бъде използван за скок до друга инструкция в програмата. Желаното място се специфицира с етикет и точка и запетая, а този етикет се поставя след goto.
Example #1 Пример за goto
<?php
goto a;
echo 'Foo';
a:
echo 'Bar';
?>
Примерът по-горе ще изведе:
Bar
Забележка: Операторът goto е наличен от PHP 5.3.
Предупреждение
Скачането в цикъл или конструкция switch не е разрешено. В този случай ще бъде изведена фатална грешка.
add a note
User Contributed Notes
goto
roman4work at gmail dot com
09-Apr-2012 03:36
f at francislacroix dot info
30-Nov-2011 01:11
The goto operator CAN be evaluated with eval, provided the label is in the eval'd code:
<?php
a: eval("goto a;"); // undefined label 'a'
eval("a: goto a;"); // works
?>
It's because PHP does not consider the eval'd code, containing the label, to be in the same "file" as the goto statement.
Ray dot Paseur at Gmail dot com
27-Oct-2011 06:59
You cannot implement a Fortran-style "computed GOTO" in PHP because the label cannot be a variable. See: http://en.wikipedia.org/wiki/Considered_harmful
<?php // RAY_goto.php
error_reporting(E_ALL);
// DEMONSTRATE THAT THE GOTO LABEL IS CASE-SENSITIVE
goto a;
echo 'Foo';
a: echo 'Bar';
goto A;
echo 'Foo';
A: echo 'Baz';
// CAN THE GOTO LABEL BE A VARIABLE?
$a = 'abc';
goto $a; // NOPE: PARSE ERROR
echo 'Foo';
abc: echo 'Boom';
?>
contact at xpertmailer dot com
07-Jul-2011 06:08
goto operator can NOT be evaluate with eval()
tweston at coldsteelstudios dot com
05-Oct-2010 08:12
In a challenge of myself for a college class I decided to use the goto to remove all while loops from my code. It was actually easy, and AS FAST as While loops.
<?PHP
$start = microtime(true);
$i = 0;
StartOfLoop:
$i++;
if($i < 1000000) goto StartOfLoop;
echo microtime(true) - $start.PHP_EOL;
$start = microtime(true);
$i = 0;
while($i < 1000000){
$i++;
}
echo microtime(true) - $start.PHP_EOL;
?>
chrisstocktonaz at gmail dot com
07-Aug-2009 03:03
Remember if you are not a fan of wild labels hanging around you are free to use braces in this construct creating a slightly cleaner look. Labels also are always executed and do not need to be called to have their associated code block ran. A purposeless example is below.
<?php
$headers = Array('subject', 'bcc', 'to', 'cc', 'date', 'sender');
$position = 0;
hIterator: {
$c = 0;
echo $headers[$position] . PHP_EOL;
cIterator: {
echo ' ' . $headers[$position][$c] . PHP_EOL;
if(!isset($headers[$position][++$c])) {
goto cIteratorExit;
}
goto cIterator;
}
cIteratorExit: {
if(isset($headers[++$position])) {
goto hIterator;
}
}
}
?>