public function testHeadKeyLastKey() { $this->assertEquals('a', Arrays::firstKey(['a' => 0, 'b' => 1])); $this->assertEquals('b', Arrays::lastKey(['a' => 0, 'b' => 1])); $this->assertEquals(null, Arrays::firstKey([])); $this->assertEquals(null, Arrays::lastKey([])); }
/** * Returns the first key of an array. * * @param array Array to retrieve the first key from. * * @return int|string The first key of the array. * @group util * * @deprecated */ function head_key(array $arr) { return \Packaged\Helpers\Arrays::firstKey($arr); }