How to access to variable in outside the map function in Laravel PHP

Question

public function test()
{
        $x = 10;
        $collection = collect([0, 10, 20]);

        $collection = $collection->map(function ($item, $key){

            return $item + $x;
        });
}

I want to access the $x variable within the map function: how to do it?
When I try to get the value I got this error message:

ErrorException: Undefined variable: x

Answer 1

You need to make sure the anonymous function has access to the variable using the use keyword.

You would use it like this:

$collection = $collection->map(function ($item, $key) use ($x) {

    return $item + $x;
});

Answer 2

public function test()
{
    $x = 10;
    $collection = collect([0, 10, 20]);

    $collection = $collection->map(function ($item) use ($x) {
        return $item + $x;
    });
}

Please note that you had return = in your code which is wrong

Answer 3

public function test()
{
    $x = 10;
    $collection = collect([0, 10, 20]);
    $collection = $collection->map(function ($item, $key) use ($x) {
       return $item + $x;
    });
}