ES6 WeakMap
ES6 WeakMap
'use strict'
let weakMap = new WeakMap();
let obj = {};
console.log(weakMap.set(obj,"hello"));
console.log(weakMap.has(obj));// true
'use strict'
let weakMap = new WeakMap();
let obj = {};
console.log(weakMap.set(obj,"hello"));
console.log(weakMap.has(obj));// true