JS實現數組的相減操作

    /**
     * 數組相減的方法 - es5
     * @param {Array} a
     * @param {Array} b
     */
    function arrSubtraction1(a, b) {
      if (!a || !b || Object.prototype.toString.call(a) !== '[object Array]' || Object.prototype.toString.call(b) !== '[object Array]') {
        throw new Error('arrSubtraction(): Wrong Param Type')
      }
      for (var i = 0, len = b.length; i < len; i++) {
        for (var j = 0, jen = a.length; j < jen; j++) {
          if (a[j] === b[i]) {
            a.splice(j, 1);
            j--
          }
        }
      }
      return a
    }

    /**
     * 數組相減的方法 - 使用es新特性
     * @param {Array} a
     * @param {Array} b
     */
    function arrSubtraction2(a, b) {
      if (Array.isArray(a) && Array.isArray(b)) {
        return a.filter(i => !b.includes(i))
      }
      throw new Error('arrSubtraction(): Wrong Param Type')
    }