laravel collection methods

1// The array we're going to return
2    $data = [];    
3// Query the users table
4$query = users::where('id', 1)->get();
5
6// Let's Map the results from [$query]
7$map = $query->map(
8    function($items){
9          $data['user_firstName'] = $items->firstName;
10          $data['user_lastName'] = $items->lastName;
11          return $data;
12        }
13    );
14
15return $map;

1$collection = collect([1,2,3,4]);
2
3$collection->each(function($item){
4    return $item*$item;
5});
6
7// [1,4,9,16]

1$collection = collect([1, 2, 3]);
2
3$collection->when(true, function ($collection) {
4    return $collection->push(4);
5});
6
7$collection->all();
8
9// [1, 2, 3, 4]

1$collection = collect([
2    ['product' => 'Desk', 'price' => 200],
3    ['product' => 'Chair', 'price' => 100],
4]);
5
6$collection->contains('product', 'Bookcase');
7
8// false

1collect([1, 2, 3])->all();
2
3// [1, 2, 3]

1$collection->each(function ($item, $key) {
2    hj
3});