//1.单数组去重复
    array_unique($arrTest)
//2.多数组去重复
    array_keys(array_flip($arr1)+array_flip($arr2))

        $arr1 = [1,2,3,4,5];
        $arr2 = [1,2,3,6,7];

        $arr3 = ['0'=>1,'1'=>2,'2'=>3,'3'=>4,'4'=>5];
        $arr4 = ['0'=>1,'1'=>2,'2'=>3,'3'=>6,'4'=>7];

        $arr5 = ['0'=>1,'a'=>2,'b'=>3,'c'=>4,'4'=>5];
        $arr6 = ['0'=>1,'a'=>2,'c'=>3,'d'=>6,'4'=>7];
        dump(array_merge($arr1, $arr2));
        dump($arr1+$arr2);
        dump(array_keys(array_flip($arr1)+array_flip($arr2)));
        echo '<br>';
        dump(array_merge($arr3, $arr4));
        dump($arr3+$arr4);
        dump(array_keys(array_flip($arr3)+array_flip($arr4)));
        echo '<br>';
        dump(array_merge($arr5, $arr6));
        dump($arr5+$arr6);