PHP foreach更改数组值 [英] PHP foreach change array value

问题描述

当您遇到如下所示的foreach循环时，我知道您可以通过$array[$key]更改数组的当前元素，但是还有一种方法可以通过$value进行更改吗?

When you have a foreach loop like below, I know that you can change the current element of the array through $array[$key], but is there also a way to just change it through $value?

foreach($array as $key => $value){

}

这可能真的很简单，但是我对PHP还是很陌生，所以请不要为我的问题而烦恼:)

It's probably really simple, but I'm quite new to PHP so please don't be annoyed by my question :)

推荐答案

要能够直接为$value分配值，您想通过在$value之前加上&来引用$value:

To be able to directly assign values to $value, you want to reference $value by preceding it with & like this:

foreach($array as $key => &$value){
    $value = 12321; //the same as $array[$key] = 12321;
}

unset($value);

在foreach循环之后，您应该执行unset($value)，因为在循环之后您仍然可以访问它.
注意:当数组是变量时，只能通过引用传递$value.以下示例不起作用:

After the foreach loop, you should do unset($value) because you're still able to access it after the loop.
Note: You can only pass $value by reference when the array is a variable. The following example won't work:

foreach(array(1, 2, 3) as $key => &$value){
    $value = 12321; //the same as $array[$key] = 12321
}

unset($value);

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