laravel：无法将对象属性推送到数组[复制]

Question

This question already has an answer here:

• PHP variables in anonymous functions 1 answer
• Reference: What is variable scope, which variables are accessible from where and what are “undefined variable” errors? 3 answers

I have stuck in a silly silly sample of code but i can't find solution. I have this code:

Route::get('/example', function(){
    $arr=[];
    Collection::all()->each(function($collection){
        $arr[]= $collection->id;
    });
    dd($arr);
}); 

and it returns to me an empty array all the time despite the fact that Collection:all() has objects inside. Can someone help me?

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Answer 1

In the each section you define function which make it with new scope for the variable.

Try the use of PHP function as:

Route::get('/example', function(){
    $arr=[];
    Collection::all()->each(function($collection) use (&$arr){
        $arr[]= $collection->id;
    });
    dd($arr);
});