assertEquals(10, Product::scalar([2, 3], [-1, 4])); $this->assertEquals(-0.1, Product::scalar([1, 4, 1], [-2, 0.5, -0.1])); $this->assertEquals(8, Product::scalar([2], [4])); //test for non numeric values $this->assertEquals(0, Product::scalar(['', null, [], new stdClass()], [null])); } }