php 突破 if 和 foreach
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9215588/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
break out of if and foreach
提问by au_stan
I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
我有一个 foreach 循环和一个 if 语句。如果找到匹配项，我需要最终退出 foreach。
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
<break out of if and foreach here>
}
}
回答by Kaii
ifis not a loop structure, so you cannot "break out of it".
if不是循环结构，因此您无法“摆脱它”。
You can, however, break out of the foreachby simply calling break. In your example it has the desired effect:
但是，您可以foreach通过简单地调用break. 在您的示例中，它具有所需的效果：
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
// will leave the foreach loop and also the if statement
break;
}
this_command_is_not_executed_after_a_match_is_found();
}
Just for completeness for others that stumble upon this question looking for an answer..
只是为了其他人偶然发现这个问题寻找答案的完整性..
breaktakes an optional argument, which defines how manyloop structures it should break. Example:
break接受一个可选参数，它定义了它应该中断多少个循环结构。例子：
foreach (array('1','2','3') as $a) {
echo "$a ";
foreach (array('3','2','1') as $b) {
echo "$b ";
if ($a == $b) {
break 2; // this will break both foreach loops
}
}
echo ". "; // never reached
}
echo "!";
Resulting output:
结果输出：
1 3 2 1 !
1 3 2 1 ！
回答by Decent Dabbler
回答by serraosays
A safer way to approach breaking a foreachor whileloop in PHP is to nest an incrementing counter variable and ifconditional inside of the original loop. This gives you tighter control than break;which can cause havoc elsewhere on a complicated page.
在 PHP 中打破foreachorwhile循环的一种更安全的方法是if在原始循环中嵌套一个递增的计数器变量和条件。这为您提供了比break;在复杂页面上的其他地方造成严重破坏的更严格的控制。
Example:
例子：
// Setup a counter
$ImageCounter = 0;
// Increment through repeater fields
while ( condition ):
$ImageCounter++;
// Only print the first while instance
if ($ImageCounter == 1) {
echo 'It worked just once';
}
// Close while statement
endwhile;
回答by Nick Constantine
For those of you landing here but searching how to break out of a loop that contains an include statement use return instead of break or continue.
对于那些登陆这里但正在寻找如何跳出包含 include 语句的循环的人，请使用 return 而不是 break 或 continue。
<?php
for ($i=0; $i < 100; $i++) {
if (i%2 == 0) {
include(do_this_for_even.php);
}
else {
include(do_this_for_odd.php);
}
}
?>
If you want to break when being inside do_this_for_even.php you need to use return. Using break or continue will return this error: Cannot break/continue 1 level. I found more details here
如果你想在 do_this_for_even.php 中中断，你需要使用 return。使用中断或继续将返回此错误：无法中断/继续 1 级。我在这里找到了更多细节
