php break jumps out of multiple loop instances_PHP tutorial

break is used in the various loops and switch statements mentioned above. Its function is to jump out of the current grammatical structure and execute the following statements. The break statement can take a parameter n, indicating the number of levels to jump out of the loop. If you want to jump out of multiple loops, you can use n to indicate the number of levels to jump out of. If there is no parameter, the default is to jump out of the current loop.

Example

The code is as follows

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代码如下	复制代码
$array = array(1,2,3,4,5,6); for($i=0;$i<10;$i++){ foreach($array as $key) { echo $key; if($key==2){ break 2; } } }

$array = array(1,2,3,4,5,6);
for($i=0;$i<10;$i++){
foreach($array as $key)
{
echo $key;
if($key==2){

break 2;
}
}
}

代码如下	复制代码
//设置编码为UTF-8，以避免中文乱码 header('Content-Type:text/html;charset=utf-8'); //执行嵌套循环，外层循环3次，内层循环2次。当执行到第2次外层循环时，使用break跳出，不执行其内层循环。 for ($i = 0; $i < 3; $i++){ echo '外层循环'.$i.' 开始 ';         for ($j = 0; $j < 2; $j++){ if ($i == 1){ break; } echo '内层循环'.$i.'-'.$j.' ';         }         echo '外层循环'.$i.' 结束 ';     }     ?>

Example

The code is as follows

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//Set encoding to UTF-8 to avoid Chinese garbled characters header('Content-Type:text/html;charset=utf-8'); //Execute a nested loop, with the outer loop 3 times and the inner loop 2 times. When the second outer loop is executed, break is used to jump out and the inner loop is not executed. for ($i = 0; $i < 3; $i++){ echo 'Outer loop'.$i.' Start '; for ($j = 0; $j < 2; $j++){                    if ($i == 1){                    break;              } echo 'Inner loop'.$i.'-'.$j.' ';          } echo 'Outer loop'.$i.' End '; } ?>

The output page results of the above code are as follows:

Outer loop 0 starts
Inner loop 0-0
Inner loop 0-1
Outer loop 0 ends

Outer loop 1 starts
Outer loop 1 ends

Outer loop 2 starts
Inner loop 2-0
Inner loop 2-1
Outer loop 2 ends

The above code is easy to understand. break is used to jump out of the current level of loop. However, unlike programming languages ​​such as Java, in PHP, we can also follow the keyword break with a number, which indicates the number of loop levels that need to be jumped out. In this way, a break statement can be used to directly jump out of multiple loops. For example:

            } echo 'Inner loop'.$i.'-'.$j.'
';

The code is as follows

代码如下

复制代码

//设置编码为UTF-8，以避免中文乱码     header('Content-Type:text/html;charset=utf-8');     //执行嵌套循环，外层循环3次，内层循环2次。当执行到第2次外层循环时，使用break 2跳出，直接跳出2层循环     for ($i = 0; $i < 3; $i++){         echo '外层循环'.$i.' 开始 ';         for ($j = 0; $j < 2; $j++){             if ($i == 1){                 break 2;    //使用break 2直接跳出2层循环                    }             echo '内层循环'.$i.'-'.$j.' ';         }         echo '外层循环'.$i.' 结束 ';     }     ?>

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//Set encoding to UTF-8 to avoid Chinese garbled characters
Header('Content-Type:text/html;charset=utf-8');

//Execute a nested loop, with the outer loop 3 times and the inner loop 2 times. When the second outer loop is executed, use break 2 to jump out and jump directly out of the second loop

for ($i = 0; $i < 3; $i++){

echo 'Outer loop'.$i.' Start
';

for ($j = 0; $j < 2; $j++){
If ($i == 1){

BREAK 2; // Use BREAK 2 to jump out of the 2 layer of loop

} echo 'Outer loop'.$i.' End

';

}

?> The page results output by the above example code are as follows: Outer loop 0 starts Inner loop 0-0 Inner loop 0-1 Outer loop 0 ends Outer loop 1 starts

Therefore, in PHP, we can use break followed by a specified number to directly jump out of a loop with a specified number of levels. Note: The number followed by break can only be a positive integer and cannot exceed the actual number of loop levels that can be jumped out. Otherwise, a fatal error will be reported.

http://www.bkjia.com/PHPjc/632635.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632635.htmlTechArticlebreak is used in the various loops and switch statements mentioned above. Its function is to jump out of the current grammatical structure and execute the following statements. The break statement can take a parameter n, which means jumping out...