最强最全深拷贝deepClone！！！

function deepClone(origin, target = {}, hash = new WeakMap()) {
   if (origin === null) return origin; // null || undefined
   else if (origin instanceof Date) return new Date(origin);
   else if (origin instanceof RegExp) return new RegExp(origin);
   else if (typeof origin !== 'object') return origin;

   // 解决引用闭环的问题
   if (hash.has(origin)) return hash.get(origin);
	// Reflect.ownKeys遍历自身所有属性
   Reflect.ownKeys(origin).forEach(function (key) {
     if (typeof origin[key] === 'object') {
       if (origin[key] instanceof Date)
         target[key] = new Date(origin[key]);
       else if (origin[key] instanceof RegExp)
         target[key] = new RegExp(origin[key]);
       else if (origin[key] instanceof Set)
         target[key] = new Set(origin[key]);
       else if (origin[key] instanceof Map)
         target[key] = new Map(origin[key]);
       else if (Object.prototype.toString.call(origin[key]) === '[object Array]') {
         target[key] = deepClone(origin[key], target[key], hash);
       }
       else if (Object.prototype.toString.call(origin[key]) === '[object Object]') {
         hash.set(origin, origin);
         target[key] = deepClone(origin[key], target[key], hash);
       } else {
         target[key] = null;
       }
     } else if (typeof origin[key] === 'function') {
       target[key] = new Function('return ' + origin[key].toString());
     }
     // 基本数据类型
     else {
       target[key] = origin[key];
     }
   });
   return target;
 }

测试代码

let s1 = Symbol('s1');

let obj = {
  a: '100',
  b: undefined,
  c: null,
  d: Symbol(2),
  e: /^\d+$/,
  f: new Date(),
  g: true,
  i: new Set([1, 2, 3, 4]),
  arr: [10, 20, 30],
  school: {
    name: 'cherry',
    [s1]: 's1'
  },
  fn: function fn() {
    console.log('fn');
  }
};

obj.h = obj;
let obj2 = deepClone2(obj);
console.log('obj', obj, 'obj2', obj2);

输出结果为

借鉴：文章1，文章2