1、从数组中删除某一个指定的元素

    Array.prototype.remove = function (val) {
      let index = this.indexOf(val);
      if (index > -1) {
        this.splice(index, 1);
      }
    };

2、去除数组中的空值

  Array.prototype.bouncer = function () {
      return this.filter(item => {/* fliter 返回结果是true的*/
        return item;
      });
    }
    let arr = [1, null, 2, 3, undefined, '', 4]
    console.log(arr)
    console.log(arr.bouncer())

3、 数组是否包含另一个数组

  function isContained(a, b) {
      /* * a是大数组b是小数组 * 数组是否包含另一个数组 */
      if (!(a instanceof Array) || !(b instanceof Array)) return false;
      if (a.length < b.length) return false;
      let aStr = a.toString();
      for (let i = 0, len = b.length; i < len; i++) {
        if (aStr.indexOf(b[i]) == -1) return false;
      }
      return true;
    }

    let arr1 = [1, 2, 3, 4, 6]
    let arr2 = [1, 2, 6, 3]
    console.log(isContained(arr1, arr2))

原型上版：

 Array.prototype.isContained = function (b) {
      if (!b instanceof Array) return false
      if (this.length < b.length) return false
      let aStr = this.toString();
      for (let i = 0, len = b.length; i < len; i++) {
        if (aStr.indexOf(b[i]) == -1) return false;
      }
      return true;
    }


    let arr1 = [1, 2, 3, 4, 6]
    let arr2 = [1, 2, 6, 3]
    console.log(arr1.isContained(arr2))

4、数组去重

  Array.prototype.uniq = function (array) {
      var temp = []; //一个新的临时数组
      for (var i = 0; i < array.length; i++) {
        if (temp.indexOf(array[i]) == -1) {
          temp.push(array[i]);
        }
      }
      return temp;
    }
    
    let arr = [1, 2, 2, 3, 4, 4, 5]
    console.log(arr)
    console.log(arr.uniq(arr))