問題描述

我有一個對象數(shù)組.對象主要有一堆屬性，因為這些是元數(shù)據(jù)對象.

I have an array of objects. The objects mainly have a bunch of properties because these are meta-data objects.

所以就像$objects[] 就像一堆具有以下屬性的項目:object->item1、object->item2等

so it is like $objects[] is like a bunch of items that have properties like: object->item1, object->item2, etc.

我想為每個對象添加一些東西，所以...

I want to add something to each of these objects, so...

foreach ($objects as &$object) {
  $object->newItem=(something I compute);
}

然后，我想將這些對象顯示為 html 中的列表.所以，我去:

then later, I want to display these objects as a list in html. So, I go:

foreach ($objects as $object) {
  <li><?php object output stuff here ?></li>
}

好的.現(xiàn)在，它工作正常，除了最后一個對象被丟棄并且倒數(shù)第二個對象顯示兩次.跆拳道??

ok. Now, it works fine, except the last object is discarded and the second to last object is displayed twice. WTF??

這對你有意義嗎?

推薦答案

如果你通過引用迭代，之后總是取消設置迭代變量:

If you iterate by reference, always unset the iteration variable afterwards:

foreach ($objects as &$object) {
      // some code
}
unset($object);

摘自 foreach 文檔:

Excerpt from the foreach documentation:

即使在 foreach 循環(huán)之后，對 $value 和最后一個數(shù)組元素的引用仍然存在.建議用unset()銷毀.

Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset().

如果您想了解為什么您的代碼的行為方式如此，這里有一些進一步的閱讀:引用和foreach

If you want to understand why your code behaves the way it behaves, here is some further reading: References and foreach

這篇關于PHP foreach by reference 在遍歷對象數(shù)組時會導致奇怪的故障的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！