You should mention the label can't be a variable
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
goto
操作符可以用来跳转到程序中的另一位置。该目标位置可以用 区分大小写 的目标名称加上冒号来标记,而跳转指令是
goto
之后接上目标位置的标记。PHP 中的 goto
有一定限制,目标位置只能位于同一个文件和作用域,也就是说无法跳出一个函数或类方法,也无法跳入到另一个函数。也无法跳入到任何循环或者
switch 结构中。可以跳出循环或者 switch,通常的用法是用 goto
代替多层的 break
。
示例 #1 goto
示例
<?php
goto a;
echo 'Foo';
a:
echo 'Bar';
?>
以上示例会输出:
Bar
示例 #2 goto
跳出循环示例
<?php
for ($i = 0, $j = 50; $i < 100; $i++) {
while ($j--) {
if ($j == 17) {
goto end;
}
}
}
echo "i = $i";
end:
echo 'j hit 17';
?>
以上示例会输出:
j hit 17
示例 #3 以下写法无效
<?php
goto loop;
for ($i = 0, $j = 50; $i < 100; $i++) {
while ($j--) {
loop:
}
}
echo "$i = $i";
?>
以上示例会输出:
Fatal error: 'goto' into loop or switch statement is disallowed in script on line 2
the problem of goto is that it is a good feature but in a large codebase it reduces the readability of the code . that's all . i try to not use it to think about the person who is going to read after me .
You can use goto to hide large HTML blocks without using echo():
<html><body>
<?php if ($hide_form_and_script) { goto label_1;} ?>
<form action="" method="post">
<!-- some HTML here -->
</form>
<script>
let a='test'; // no need to escape nested quotes as with echo()
// some JavaScript here
</script>
<?php label_1: ?>
</body></html>