declare
NB: using return to exit a command-line script will not use the return value as the script's return value. To do that, you need to use, eg, exit(1);
return
Si appelée depuis une fonction, la commande return() termine immédiatement la fonction, et retourne l'argument qui lui est passé. return() interrompt aussi l'exécution de commande eval() ou de scripts.
Si appelée depuis l'environnement global, l'exécution du script est interrompue. Si le script courant était include() ou require(), alors le contrôle est rendu au script appelant, et la valeur retournée sera utilisée comme résultat de la fonction include(). Si return() est appelée depuis le script principal, alors l'exécution du script s'arrête. Si le script courant est auto_prepend_file ou auto_append_file dans le fichier php.ini, alors l'exécution du script s'arrête.
Pour plus d'informations, voyez retourner des valeurs.
Note: Notez que puisque return() est une structure de langage, et non une fonction, les parenthèses entourant les arguments ne sont pas nécessaires. Il est classique de les oublier et vous devriez le faire car PHP travaillera moins dans ce cas.
Note: Vous ne devriez jamais utiliser les parenthèses autour de la variable retournée lorsque vous la retournez pas référence, car cela ne fonctionnera pas. Vous ne pouvez retourner que les variables par référence, et non le résultat du traitement. Si vous utilisez return ($a);, alors vous ne retournez pas une variable mais le résultat de l'expression ($a) (qui est, bien sûr, la valeur de $a).
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User Contributed Notesreturn
pgl at yoyo dot org
31-Jul-2009 03:23
31-Jul-2009 03:23
fyrye
31-Jul-2009 10:25
31-Jul-2009 10:25
A side note when you return a conditional value the variable type will inherit its type of Boolean
For example
<?php
function foo($SQL){
$conTemp = new mysqli("locahost", "root", "", "");
$conTemp->select_db("MyDB");
return $conTemp->query($SQL) or die("Query Failed!");
}
$result = foo("SELECT UserName FROM Users LIMIT 1");
echo gettype($result); //returns Boolean instead of object or die
?>
Instead be explicit with your function like so
<?php
function foo($SQL){
$conTemp = new mysqli("locahost", "root", "", "");
$conTemp->select_db("MyDB");
if(!$result = $conTemp->query($SQL)){
return die("Query Failed");
}
return $result;
}
$result = foo("SELECT UserName FROM Users LIMIT 1");
echo gettype($result); //Now will return Object or die
?>
list at regularoddity dot com
07-Oct-2008 04:26
07-Oct-2008 04:26
As obvious as it may seem, it might still be useful to point out that return called without any value returns null.
<?php
function test() {
return;
}
print gettype(test()) . "\n";
print (test()?'true':'false') . "\n";
print (!test()?'true':'false') . "\n";
print (test() === false?'true':'false') . "\n";
?>
This returns:
NULL
false
true
false
andrew at neonsurge dot com
15-Aug-2008 08:40
15-Aug-2008 08:40
Response to stoic's message below...
I believe the way you've explained this for people may be a bit confusing, and your verbiage is incorrect. Your script below is technically calling return from a global scope, but as it says right after that in the description above... "If the current script file was include()ed or require()ed, then control is passed back to the calling file". You are in a included file. Just making sure that is clear.
Now, the way php works is before it executes actual code it does what you call "processing" is really just a syntax check. It does this every time per-file that is included before executing that file. This is a GOOD feature, as it makes sure not to run any part of non-functional code. What your example might have also said... is that in doing this syntax check it does not execute code, merely runs through your file (or include) checking for syntax errors before execution. To show that, you should put the echo "b"; and echo "a"; at the start of each file. This will show that "b" is echoed once, and then "a" is echoed only once, because the first time it syntax checked a.php, it was ok. But the second time the syntax check failed and thus it was not executed again and terminated execution of the application due to a syntax error.
Just something to help clarify what you have stated in your comments.
stoic
06-Jun-2008 01:21
06-Jun-2008 01:21
Just to clear things up, if using return on a global scope it will end EXECUTION but NOT PROCESSING.
for example:
file a.php
<?php
if(defined("A")) return;
define("A", true);
echo "Hello";
?>
file b.php
<?php
include("a.php");
include("a.php");
?>
will output "Hello" only once.
but if file a.php is
<?php
if(defined("A")) return;
define("A", true);
function foo(){
}
?>
running file b.php will produce error:
Fatal Error: Cannot redeclare foo()...
Denis.Gorbachev
02-Dec-2007 10:06
02-Dec-2007 10:06
direct true 0.59850406646729
direct false 0.62642693519592
indirect true 0.75077891349792
indirect false 0.73496103286743
It is generally more true, because indirect method implies creating additional variable and assigning a value to it.
But, you know, "results may vary".
mr dot xanadu at gmail dot com
12-Oct-2007 08:56
12-Oct-2007 08:56
I was wondering what was quicker:
- return a boolean as soon I know it's value ('direct') or
- save the boolean in a variable and return it at the function's end.
<?php
$times = 50000;
function return_direct ($boolean)
{
if ($boolean == true)
{
return true;
}
return false;
}
function return_indirect ($boolean)
{
$return = false;
if ($boolean == true)
{
$return = true;
}
return $return;
}
/* Direct, return true */
$time_start = microtime(true);
for ($i = 1; $i <= $times; $i++)
{
return_direct(true);
}
$time_end = microtime(true);
$time_direct_true = $time_end - $time_start;
/* Direct, return false */
$time_start = microtime(true);
for ($i = 1; $i <= $times; $i++)
{
return_direct(false);
}
$time_end = microtime(true);
$time_direct_false = $time_end - $time_start;
/* Indirect, return true */
$time_start = microtime(true);
for ($i = 1; $i <= $times; $i++)
{
return_indirect(true);
}
$time_end = microtime(true);
$time_indirect_true = $time_end - $time_start;
/* Direct, return false */
$time_start = microtime(true);
for ($i = 1; $i <= $times; $i++)
{
return_indirect(false);
}
$time_end = microtime(true);
$time_indirect_false = $time_end - $time_start;
echo "<pre>";
echo "direct true\t" . $time_direct_true;
echo "\ndirect false\t" . $time_direct_false;
echo "\nindirect true\t" . $time_indirect_true;
echo "\nindirect false\t" . $time_indirect_false;
echo "<pre>";
?>
Representative results:
direct true 0.163973093033
direct false 0.1270840168
indirect true 0.0733940601349
indirect false 0.0742440223694
Conclusion: saving the result in a variable appears to be faster. (Please note that my test functions are very simple, maybe it's slower on longer functions)
Spacecat
25-Jul-2007 01:13
25-Jul-2007 01:13
regardez this code:
print pewt( "hello!" );
function pewt( $arg )
{
include( "some_code.inc" );
}
some_code.inc:
return strtoupper( $arg );
.. after much hair pulling, discovered why nothing was being returned by the "some_code.inc" code in the function .. the return simply returns the result TO the function (giving the include function a value), not to the CALLING (print pewt). This works:
print pewt( "hello!" );
function pewt( $arg )
{
return include( "some_code.inc" );
}
So, RETURN works relative to block it is executed within.
warhog at warhog dot net
18-Dec-2005 08:28
18-Dec-2005 08:28
for those of you who think that using return in a script is the same as using exit note that: using return just exits the execution of the current script, exit the whole execution.
look at that example:
a.php
<?php
include("b.php");
echo "a";
?>
b.php
<?php
echo "b";
return;
?>
(executing a.php:) will echo "ba".
whereas (b.php modified):
a.php
<?php
include("b.php");
echo "a";
?>
b.php
<?php
echo "b";
exit;
?>
(executing a.php:) will echo "b".