Laravel 5 Collections: Retrieving the Collection Element's Keys With keys

The keys method is used to retrieve the keys of all items in the collection. The keys method returns a new Collection instance.

The behavior of the keys method is similar to PHP's array_keys function.

#Signature

1public function keys();

#Example Use

The following code example demonstrates the usage of the keys method:

1use Illuminate\Support\Collection;
2 
3// Create a new collection.
4$collection = new Collection([
5    'first', 'second', 'third'
6]);
7 
8$keys = $collection->keys();

After the above code executes, the $keys variable would contain a value similar to the following output:

1object(Illuminate\Support\Collection)
2  protected 'items' =>
3    array
4      0 => int 0
5      1 => int 1
6      2 => int 2

The following shows a sample, with output, of a collection containing items represented by an associative array:

 1use Illuminate\Support\Collection;
 2 
 3 
 4// Create a new collection.
 5$collection = new Collection([
 6    'first'  => 'I am first',
 7    'second' => 'I am second',
 8    'third'  => 'I am third'
 9]);
10 
11$keys = $collection->keys();

The $keys variable would now contains a value similar to the following output:

1object(Illuminate\Support\Collection)
2  protected 'items' =>
3    array
4      0 => string 'first'
5      1 => string 'second'
6      2 => string 'third'

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