(PHP 4, PHP 5, PHP 7)
break ends execution of the current for, foreach, while, do-while or switch structure.
break accepts an optional numeric argument which tells it how many nested enclosing structures are to be broken out of. The default value is 1, only the immediate enclosing structure is broken out of.
<?php
$arr = array('one', 'two', 'three', 'four', 'stop', 'five');
while (list(, $val) = each($arr)) {
if ($val == 'stop') {
break; /* You could also write 'break 1;' here. */
}
echo "$val<br />\n";
}
/* Using the optional argument. */
$i = 0;
while (++$i) {
switch ($i) {
case 5:
echo "At 5<br />\n";
break 1; /* Exit only the switch. */
case 10:
echo "At 10; quitting<br />\n";
break 2; /* Exit the switch and the while. */
default:
break;
}
}
?>
| Version | Description |
|---|---|
| 5.4.0 | break 0; is no longer valid. In previous versions it was interpreted the same as break 1;. |
| 5.4.0 | Removed the ability to pass in variables (e.g., $num = 2; break $num;) as the numerical argument. |
A break statement that is in the outer part of a program (e.g. not in a control loop) will end the script. This caught me out when I mistakenly had a break in an if statement
i.e.
<?php
echo "hello";
if (true) break;
echo " world";
?>
will only show "hello"
vlad at vlad dot neosurge dot net wrote on 04-Jan-2003 04:21
> Just an insignificant side not: Like in C/C++, it's not
> necessary to break out of the default part of a switch
> statement in PHP.
It's not necessary to break out of any case of a switch statement in PHP, but if you want only one case to be executed, you have do break out of it (even out of the default case).
Consider this:
<?php
$a = 'Apple';
switch ($a) {
default:
echo '$a is not an orange<br>';
case 'Orange':
echo '$a is an orange';
}
?>
This prints (in PHP 5.0.4 on MS-Windows):
$a is not an orange
$a is an orange
Note that the PHP documentation does not state the default part must be the last case statement.
If the numerical argument is higher than the number of things which can be broken out of, it seems to me like the execution of the entire program is stopped.
My program had 8 nested loops. Didn't bother counting them, but wrote: break 10. - Result: Code following the loops was not processed.
Here is a function that returns specific files in an array, with all of the details. Includes some basic garbage checking.
Variables
$source_folder // the location of your files
$ext // file extension you want to limit to (i.e.: *.txt)
$sec // if you only want files that are at least so old.
$limit // number of files you want to return
The function
function glob_files($source_folder, $ext, $sec, $limit){
if( !is_dir( $source_folder ) ) {
die ( "Invalid directory.\n\n" );
}
$FILES = glob($source_folder."\*.".$ext);
$set_limit = 0;
foreach($FILES as $key => $file) {
if( $set_limit == $limit ) break;
if( filemtime( $file ) > $sec ){
$FILE_LIST[$key]['path'] = substr( $file, 0, ( strrpos( $file, "\\" ) +1 ) );
$FILE_LIST[$key]['name'] = substr( $file, ( strrpos( $file, "\\" ) +1 ) );
$FILE_LIST[$key]['size'] = filesize( $file );
$FILE_LIST[$key]['date'] = date('Y-m-d G:i:s', filemtime( $file ) );
$set_limit++;
}
}
if(!empty($FILE_LIST)){
return $FILE_LIST;
} else {
die( "No files found!\n\n" );
}
}
So....
$source_folder = "c:\temp\my_videos";
$ext = "flv"; // flash video files
$sec = "7200"; // files older than 2 hours
$limit = 2; // Only get 2 files
print_r(glob_files($source_folder, $ext, $sec, $limit));
Would return:
Array
(
[0] => Array
(
[path] => c:\temp\my_videos\
[name] => fluffy_bunnies.flv
[size] => 21160480
[date] => 2007-10-30 16:48:05
)
[1] => Array
(
[path] => c:\temp\my_videos\
[name] => synergymx.com.flv
[size] => 14522744
[date] => 2007-10-25 15:34:45
)
<?php
/*
break :break command exits the innermost loop construct which contains it.
break ends execution of the current for, foreach, while, do-while or switch structure.
break accepts an optional numeric argument which tells it how many nested enclosing structures are to be broken out of.
You can view various output by changing comparision operator(<,==,>) or value of $limit
*/
$to_square_root=65536;
$i=1;
$limit=4;
while (true) {
$square_root=sqrt($to_square_root);
echo "Square Root of $to_square_root is $square_root.<BR>";
$to_square_root=$square_root;
$i=$i+1;
if ($i>$limit) // if ($i<$limit) is used, loop breaks on very first execution
break;
}
$loop=$i-1;
echo "This loop is executes for $loop times.";
/* Above codes produces following output in browser
Square Root of 65536 is 256
Square Root of 256 is 16
Square Root of 16 is 4
Square Root of 4 is 2
This loop is executes for 4 times
*/
?>
Just to note: break doesn't work within included file, results in fatal error.
main.php:
<?php
switch ( $i )
{
case '1': // Works
echo "$i";
break;
case '2': // Works
require( 'include1.inc' );
break;
case '3': // Doesn't work
require( 'include2.inc' );
break;
case '4': // Doesn't work, same reason
require( 'include2.inc' );
default: // Works
echo "$i";
}
?>
include1.inc:
<?php
echo "$i";
?>
include2.inc:
<?php
echo "$i";
break;
?>
I didn't find this documented anywhere.
<?php
echo 'Hello ';
foreach (array('1','2','3','4','5') as $id) {
echo $id . ' ';
if ($id == 3)
break;
}
}
echo ' world.';
?>
Prints:
Hello 1 2 3 world.
It should be noted prior to PHP 7 you could use break in much the way you could use return. However as of PHP 7 this will produce a fatal error.
function a() {
if (1 === 1) {
break;
}
echo 'something';
}
The above will break in php 7 but will not produce any error in previous versions.
If you wonder how to end execution of a function (as I did), it's that simple: return
function foo($a) {
if(!$a) return;
echo 'true';
// some other code
}
foo(true) will echo 'true', foo(false) won't echo anything (as return ends execution of the function. Of course, therefore there is no need for 'else' before 'echo').
Note that the break argument accepts any expression, including a function result. So you may want to dynamically choose the loop level to break from:
<?php
// the print() function returns 1
function icarus()
{
while(print('sea level, '))
while(print('through the clouds, '))
while(print('close the Sun - '))
break rand(print('FEATHERS LOSS! - '), 3);
print('no feathers remaining.');
}
icarus();
?>
"Just an insignificant side not: Like in C/C++, it's not necessary to break out of the default part of a switch statement in PHP."
--Yes it is, it's just that traditionally default: is the last entry of a switch and so nothing happens after.
-If it was, for whatever reason, not the last entry the script would bawk, there is no implicit break; associated with switch.
The previous note has a somewhat stupid author: why didn't you put an example?
If I got it right, "case"s in "switch"es always need a "break".
So this switch ...
<?php
switch ( $i ) {
case '1': // Works
echo "$i=1";
break;
case '2': // Works
require( 'include1.inc' );
break;
case '3': // Doesn't work
require( 'include2.inc' );
break;
case '4': // Doesn't work, same reason
require( 'include2.inc' );
default: // Works
echo "$i";
}
?>
... has a problem in case "4" in that it doesn't have a "break" and this file...
include2.inc:
<?php
echo "$i";
break;
?>
... has a problem in that it has a "break" that is not in a "control structure" (like while, for...).
In the same way, although "include2.inc" is "include"d (obvioulsy) in the <?php ?> script (of main.php), it still need another <?php ?> to wrap its content.
Likewise,
main.php
<?php
echo "<div>This div is generated by php</div>\n";
include 'file.php'; ?>
echo "<div>This div is also generated by php</div>\n";
file.php:
<div>This is an old static HTML div.</div>
... doesn't require "file.php" content to start with "?>" (exit php) and end with "<?php" (go back to line 3 of main.php). This would FAIL.
(See strange structure ALWAYS fail"?>!)
Does this really need documentation?
To make it very clear, if you use "break" with no numerical argument, that's the same as doing "break 1".
"break 0", while allowed, does nothing.
Your break doesn't work because it isn't within a control structure. I use includes that have breaks and they work fine because they are in a control structure (foreach, while, etc.)
To add to the responses given to "vlad at vlad dot neosurge dot net" - I'd like to note the lack of automatic breaking in 'default' can be a very good thing. Consider this useful snippet:
<?php
switch((string) $_REQUEST['mode']) {
default:
$_REQUEST['mode'] = "search";
// fall through...
case 'search' :
case 'list' :
case 'add' :
case 'edit' :
require(dirname(__FILE__)."/incs/".$_REQUEST['mode'].".php");
break;
}
?>
I personally find that far easier to look at than, for example:
<?php
$valid_modes = array('search','list','add','edit');
if (in_array($_REQUEST['mode'],$valid_modes)) {
require(dirname(__FILE__)."/incs/".$_REQUEST['mode'].".php");
} else {
require(dirname(__FILE__)."/incs/search.php");
}
?>
...and it even has the added benefit that the switch() variant only has one require() statement, which makes for easier maintenance, e.g. if the directory changes, or what-have-you.
(Consider the above pseudocode, please, it's not tested - it's code illustrating a point only.)
For Perl or C programmers...
break is equivelant to last
while(false ! == ($site = $d->read()) ) {
if ($site === 'this') {
break; // in perl this could be last;
}
}
