<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title></head><body> <script> function A(){ this.name = 'yao'; this.age = '30'; this.say = function () { return this.name; } // console.log(arguments); } //A(); // var obj = { // a: 1, // b:2, // c: new Date() // } var obj = new A(11); function deepClone(obj) { if(obj == null) return null; if(typeof obj !== 'object') return obj; if(obj instanceof RegExp) { return new RegExp(obj); } if(obj instanceof Date) { return new Date(obj); } let newObj = new obj.constructor; for(let key in obj) { if(obj.hasOwnProperty(key)) { newObj[key] = deepClone(obj[key]); } } return newObj; } let obj2 = deepClone(obj); console.log(obj, obj2); console.log(obj.constructor, obj2.constructor); console.log(obj == obj2); </script></body></html>