php 打破嵌套循环
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/11609532/
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
Breaking the nested loop
提问by user1355300
I'm having problem with nested loop. I have multiple number of posts, and each post has multiple number of images.
我遇到了嵌套循环问题。我有多个帖子，每个帖子都有多个图片。
I want to get total of 5 images from all posts. So I am using nested loop to get the images, and want to break the loop when the number reaches to 5. The following code will return the images, but does not seem to break the loop.
我想从所有帖子中总共获取 5 张图片。所以我使用嵌套循环来获取图像，并希望在数字达到5时中断循环。以下代码将返回图像，但似乎没有中断循环。
foreach($query->posts as $post){
if ($images = get_children(array(
'post_parent' => $post->ID,
'post_type' => 'attachment',
'post_mime_type' => 'image'))
){
$i = 0;
foreach( $images as $image ) {
..
//break the loop?
if (++$i == 5) break;
}
}
}
回答by dynamic
Unlike other languages such as C/C++, in PHP you can use the optional param of break like this:
与 C/C++ 等其他语言不同，在 PHP 中，您可以像这样使用 break 的可选参数：
break 2;
In this case if you have two loops such that:
在这种情况下，如果您有两个循环，则：
while(...) {
while(...) {
// do
// something
break 2; // skip both
}
}
break 2will skip both while loops.
break 2将跳过两个 while 循环。
Doc: http://php.net/manual/en/control-structures.break.php
文档：http: //php.net/manual/en/control-structures.break.php
This makes jumping over nested loops more readable than for example using gotoof other languages
这使得跳过嵌套循环比使用goto其他语言更具可读性
回答by periklis
Use a while loop
使用while循环
<?php
$count = $i = 0;
while ($count<5 && $query->posts[$i]) {
$j = 0;
$post = $query->posts[$i++];
if ($images = get_children(array(
'post_parent' => $post->ID,
'post_type' => 'attachment',
'post_mime_type' => 'image'))
){
while ($count < 5 && $images[$j]) {
$count++;
$image = $images[$j++];
..
}
}
}
?>
