Simple way to change the value of a variable within a closer function

If you want to change a value of a variable within a closer function, use the & before each variable.

1 
2$roles = [];
3 
4$users->each(function ($user) use ($roles) {
5    $roles = $user->roles;
6});

Output

1// [] empty array

Use the & before the variable.

1$users->each(function ($user) use ($roles) {
2    $roles = $user->roles;
3});

Output

1// array of rules