一，Array.isArray() 用于确定传递的值是否是一个 Array

Array.isArray([1, 2, 3]);  // trueArray.isArray({foo: 123}); // falseArray.isArray("foobar");   // falseArray.isArray(undefined);  // false

文档：https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray

 

二，typeof

console.log(typeof 42);// expected output: "number"console.log(typeof 'blubber');// expected output: "string"console.log(typeof true);// expected output: "boolean"console.log(typeof declaredButUndefinedVariable);// expected output: "undefined";

文档：https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/typeof

 

三，Object.prototype.toString.call

console.log(Object.prototype.toString.call("jerry"));//[object String]console.log(Object.prototype.toString.call(12));//[object Number]console.log(Object.prototype.toString.call(true));//[object Boolean]console.log(Object.prototype.toString.call(undefined));//[object Undefined]console.log(Object.prototype.toString.call(null));//[object Null]console.log(Object.prototype.toString.call({name: "jerry"}));//[object Object]console.log(Object.prototype.toString.call(function(){}));//[object Function]console.log(Object.prototype.toString.call([]));//[object Array]console.log(Object.prototype.toString.call(new Date));//[object Date]console.log(Object.prototype.toString.call(/\d/));//[object RegExp]function Person(){};console.log(Object.prototype.toString.call(new Person));//[object Object]

文档：https://www.cnblogs.com/youhong/p/6209054.html