You should mention the label can't be a variablegoto
(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 = $i";
?>以上示例会输出：
Fatal error: 'goto' into loop or switch statement is disallowed in script on line 2
＋add a note
User Contributed Notes 6 notes
devbyjesus at example dot com ¶
1 year ago
the problem of goto is that it is a good feature but in a large codebase it reduces the readability of the code . that's all . i try to not use it to think about the person who is going to read after me .
Anonymous ¶
2 months ago
Example to exit loops:
for ($i = 0; $i < 10; $i++) {
for ($j = 0; $j < 10; $j++) {
if ($condition) {
goto exit;
}
}
}
exit:
echo "Out of the loop.";
BPI ¶
1 year ago
You can jump inside the same switch. This can be usefull to jump to default
<?php
$x=3;
switch($x){
case 0:
case 3:
print($x);
if($x)
goto def;
case 5:
$x=6;
default:
def:
print($x);
}
?>
PHP_is_still_great ¶
2 years ago
// goto is STILL a good feature if you know how to use it.
// Just don't use it in loops.
// Example:
$sql = "DELETE FROM sometable WHERE id=?;";
$stmt = $conn->prepare($sql);
if (!$stmt) {
echo "ERR prepare_fail";
goto End;
}
$bind = $stmt->bind_param('i', $id);
if (!$bind) {
echo "ERR bind_fail";
goto End;
}
$exec = $stmt->execute();
if (!$exec) {
echo "ERR exec_fail";
goto End;
}
if (isset($_POST['file'])) {
$file = "../" . $_POST['file'];
if (is_file($file)) { unlink($file); }
}
echo "OK delete_success" ;
End:
$stmt->close();
$conn->close();
exit;
/*
instead of repeating the $stmt->close() and $conn->close(),
we save a few lines by adding a goto and just close everything at the end.
*/
firstbitrix at ya dot ru ¶
1 year ago
I found a good way to use goto for walking through a foreach iteration one another time in order not to walk through whole array once again or not to use special and mostly complex if...else constructions.
But don't forget to make an exit from the goto loop if the iteration of rewalking reaches to many attemptions.
Brief example:
foreach ($fooArray as $foo) {
$attemptionLimit = 0;
restartIteration:
if (++$attemptionLimit > 10) {
continue;
}
$result = $foo->doSomething();
if (!$result) {
$foo->doSomethingElse($attemptionLimit);
goto restartIteration;
} else {
echo "Done!";
}
}