target instanceof type
Note: typeof cannot be used, because except for primitive types and functions, all are objects. (Including null); Do not use Object to test, because Array belongs to a subclass of object
var a = {}
var b = []
// 【注意】不要用Object来测试，因为Array属于Object的子类
console.log(a instanceof Array) //false
console.log(b instanceof Array) //true
target.constructor
Since each instance will inherit the properties of the prototype, and the prototype's constructor property will point to its own constructor; custom classes can be displayed
var a = {}
var b = []
console.log(a.constructor) // [Function: Object]
console.log(b.constructor) //[Function: Array]Object.prototype.toString.call(target)
1. Each object comes with a default toString function to print the type of the object
2. However, some custom objects may rewrite toString. Therefore, call from the original object prototype, and then use call to replace this environment
3. Unable to display custom classes, all will display Object
var a = {}
var b = []
console.log(Object.prototype.toString.call(a)) // [object Object]
console.log(Object.prototype.toString.call(b)) // [object Array]
Reprinted from: https://www.wolai.com/mary/rPktXJ2xocawfXnX1vqTeD