Detailed explanation of return exit break contiue in php

Return, break and continue are language structures, just like if statements, but exit is a function.

1.exit function

Function: Output a message and terminate the current script

Output a message and terminate the current script.

If a piece of text includes multiple scripts starting with , exit exits all scripts.

For example, if a PHP text includes the following code, it will not be output as world.

echo "hello";

exit;

echo "world";

Syntax format: void means no return value.

void exit ([ string $status ] )

void exit ( int $status )

If status is a string, this function prints the status just before exiting.

If status is a string, this function prints status before the script exits.

If status is an integer, that value will also be used as the exit status. Exit statuses should be in the range 0 to 254, the exit status 255 is reserved by PHP and shall not be used. The status 0 is used to terminate the program successfully.

If status is an integer, this integer will be used as the exit status. Exit status should be from 0 to 254, exit status 255 is reserved by PHP and is prohibited from use. Status 0 is used to indicate successful termination of the procedure.

2. Usage of return language structure

Function: Terminate the execution of the function and return a value from the function

3.break and continue

Used in for, foreach, while, do..while or switch structures.

break ends the execution of the current for, foreach, while, do..while or switch structure.

break can accept an optional numeric parameter to determine how many loops to break out of.

Code:

$arr = array ('one', 'two', 'three', 'four', 'stop', 'five');

while (list (, $val) = each ($arr)) {

if ($val == 'stop') {

break;

}

echo "$val
n";

}

$i = 0;

while (++$i) {

switch ($i) {

case 5:

echo "At 5
n";

break 1;

case 10:

echo "At 10; quitting
n";

break 2;

default:

break;

}

continue is used in a loop structure to skip the remaining code in this loop and start executing the next loop of this loop structure.

Note: Note that in PHP the switch statement is considered a loop structure for continue purposes.

continue accepts an optional numeric parameter to determine how many loops to skip to the end of the loop.

Code:

while (list ($key, $value) = each ($arr)) {

if (!($key % 2)) { // skip odd members

continue;

}

do_something_odd ($value);

}

$i = 0;

while ($i++ < 5) {

echo "Outer
n";

while (1) {

echo " Middle
n";

while (1) {

echo " Inner
n";

continue 3;

}

echo "This never gets output.
n";

}

echo "Neither does this.
n";

}

Related labels：

break php return and Detailed explanation

source：php.cn

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Detailed explanation of return exit break contiue in php_PHP tutorial