Why does PHP use the array_combine method to affect the original array?

Please see the code below:

There are two arrays before processingarrTitleandarrHref,

The content ofarrTitleis as follows:

arrHrefThe content is as follows:

//将title数组中首元素取出,作为栏目标题 foreach ($arrTitle as &$title) { $text [] = $title[0]; unset($title[0]); } //将href数组中首元素取出,作为栏目url foreach ($arrHref as &$href) { $url [] = $href[0]; unset($href[0]); } print_r($arrTitle); //重新组织title项 $title = array_combine($text, $url); print_r($arrTitle);die;

Run the above PHP code to extract and remove the first element of each item in title and href. However, the problem arises. Before executingarray_combine,$arrTitlelooks like this:

However, after executingarray_combine,$arrTitlebecomes like this:

Why, the last element of$arrTitlebecomes the result ofarray_combine(), but thearray_combine()function does not modify$arrTitle?

Reply content:

Please see the code below:

There are two arrays before processingarrTitleandarrHref,

The content ofarrTitleis as follows:

arrHrefThe content is as follows:

//将title数组中首元素取出,作为栏目标题 foreach ($arrTitle as &$title) { $text [] = $title[0]; unset($title[0]); } //将href数组中首元素取出,作为栏目url foreach ($arrHref as &$href) { $url [] = $href[0]; unset($href[0]); } print_r($arrTitle); //重新组织title项 $title = array_combine($text, $url); print_r($arrTitle);die;

Run the above PHP code to extract and remove the first element of each item in title and href. However, the problem arises. Before executingarray_combine,$arrTitlelooks like this:

However, after executingarray_combine,$arrTitlebecomes like this:

Why, the last element of$arrTitlebecomes the result ofarray_combine(), but thearray_combine()function does not modify$arrTitle?

**$title** = array_combine($text, $url); 

$title here has the same name as $title in the loop above, just change the name. There is no block scope in php.

This bug has been resolved. Thanks to @whyreal for pointing out the duplicate name issue.

Since in the foreach loop, the array is traversed inreference mode, when the loop ends,$titlepoints to the last set of elements of$arrTitle.

Since PHP does not have a block-level scope, in $title = array_combine($arr1, $arr2), then the $title also modifies the last group of elements it points to$arrTitle, resulting in a bug.

Modify the name behind$titleto eliminate this bug.