检测数据类型的方法 instanceof typeof 终极检测类型 Object.prototype.toString.call()()

检测数据类型的方法:

       1.instanceof 

       2.typeof       

       3. 终极检测类型 Object.prototype.toString.call()

      =======================================

//   function Father() {
      //     this.sing = function () {
      //       //   console.log("我是父级");
      //     };
      //   }
      //   const zjl = new Father();
      //   zjl.sing();
      //   console.log(zjl instanceof Father); //true
      //   console.log(zjl instanceof Object); //true
      //   console.log(zjl instanceof Array); //false
      //   console.log(Array instanceof Object); //true Array检测出来的类型是Object
      //   console.log([1, 4, 5, 7] instanceof Object); // true
      //   console.log([1, 4, 5, 7] instanceof Array); // true

      //===========
      //   console.log(Object.prototype.toString.call(1)); // [object Number]
      //   console.log(Object.prototype.toString.call("我是字符串")); //[object String]
      //   console.log(Object.prototype.toString.call(undefined)); //[object Undefined]
      //   console.log(Object.prototype.toString.call(null)); //[object Null]
      //   console.log(Object.prototype.toString.call(true)); //[object Boolean]
      //   console.log(Object.prototype.toString.call({})); //[object Object]
      //   console.log(Object.prototype.toString.call(function () {})); //[object Function]
      //   console.log(Object.prototype.toLocaleString.call(NaN)); //NaN
      //   console.log(Object.prototype.toString.call(Number)); //[object Function]

      //   console.log(Object.prototype.toString.call(String)); //[object Function]
————————

检测数据类型的方法:

       1.instanceof 

       2.typeof       

       3. 终极检测类型 Object.prototype.toString.call()

      =======================================

//   function Father() {
      //     this.sing = function () {
      //       //   console.log("我是父级");
      //     };
      //   }
      //   const zjl = new Father();
      //   zjl.sing();
      //   console.log(zjl instanceof Father); //true
      //   console.log(zjl instanceof Object); //true
      //   console.log(zjl instanceof Array); //false
      //   console.log(Array instanceof Object); //true Array检测出来的类型是Object
      //   console.log([1, 4, 5, 7] instanceof Object); // true
      //   console.log([1, 4, 5, 7] instanceof Array); // true

      //===========
      //   console.log(Object.prototype.toString.call(1)); // [object Number]
      //   console.log(Object.prototype.toString.call("我是字符串")); //[object String]
      //   console.log(Object.prototype.toString.call(undefined)); //[object Undefined]
      //   console.log(Object.prototype.toString.call(null)); //[object Null]
      //   console.log(Object.prototype.toString.call(true)); //[object Boolean]
      //   console.log(Object.prototype.toString.call({})); //[object Object]
      //   console.log(Object.prototype.toString.call(function () {})); //[object Function]
      //   console.log(Object.prototype.toLocaleString.call(NaN)); //NaN
      //   console.log(Object.prototype.toString.call(Number)); //[object Function]

      //   console.log(Object.prototype.toString.call(String)); //[object Function]