(PHP 4, PHP 5)
exit — Output a message and terminate the current script
Terminates execution of the script. Shutdown functions and object destructors will always be executed even if exit() is called.
If status is a string, this function prints the status just before exiting.
If status is an integer, that value will be used as the exit status and not printed. 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.
Note: PHP >= 4.2.0 does NOT print the status if it is an integer.
没有返回值。
Example #1 exit() example
<?php
$filename = '/path/to/data-file';
$file = fopen($filename, 'r')
or exit("unable to open file ($filename)");
?>
Example #2 exit() status example
<?php
//exit program normally
exit;
exit();
exit(0);
//exit with an error code
exit(1);
exit(0376); //octal
?>
Example #3 Shutdown functions and destructors run regardless 以上例程会输出：
<?php
class Foo
{
public function __destruct()
{
echo 'Destruct: ' . __METHOD__ . '()' . PHP_EOL;
}
}
function shutdown()
{
echo 'Shutdown: ' . __FUNCTION__ . '()' . PHP_EOL;
}
$foo = new Foo();
register_shutdown_function('shutdown');
exit();
echo 'This will not be output.';
?>
Shutdown: shutdown()
Destruct: Foo::__destruct()
Note: 因为是一个语言构造器而不是一个函数，不能被 可变函数 调用。
Note:
This language construct is equivalent to die().