laravel-5

Collections 295
flatten() {#collection-method}
The flatten method flattens a multi-dimensional collection into a single dimension:
1 $collection = collect(['name' => 'taylor', 'languages' => ['php', 'javascript']]\
2 );
3
4 $flattened = $collection->flatten();
5
6 $flattened->all();
7
8 // ['taylor', 'php', 'javascript'];
You may optionally pass the function a “depth” argument:
1 $collection = collect([
2 'Apple' => [
3 ['name' => 'iPhone 6S', 'brand' => 'Apple'],
4 ],
5 'Samsung' => [
6 ['name' => 'Galaxy S7', 'brand' => 'Samsung']
7 ],
8 ]);
9
10 $products = $collection->flatten(1);
11
12 $products->values()->all();
13
14 /*
15 [
16 ['name' => 'iPhone 6S', 'brand' => 'Apple'],
17 ['name' => 'Galaxy S7', 'brand' => 'Samsung'],
18 ]
19 */
Here, calling flatten without providing the depth would have also flattened the nested arrays,
resulting in ['iPhone 6S', 'Apple', 'Galaxy S7', 'Samsung']. Providing a depth allows you to
restrict the levels of nested arrays that will be flattened.