function deepCopy(obj) {
// hash表泻轰，記錄所有的對象的引用關系
let map = new WeakMap();
function dp(obj) {
let result = null;
let keys = Object.keys(obj);
let key = null,
temp = null,
existobj = null;
existobj = map.get(obj);
//如果這個對象已經被記錄則直接返回
if (existobj) {
return existobj;
}
result = {}
map.set(obj, result);
for (let i = 0, len = keys.length; i < len; i++) {
key = keys[i];
temp = obj[key];
if (temp && typeof temp === 'object') {
result[key] = dp(temp);
} else {
result[key] = temp;
}
}
return result;
}
return dp(obj);
}
測試用例
const obj1 = {
x: 1
}
// obj1.z = obj1;
const obj2 = {
x: 2
}
obj1.next = obj2;
obj2.next = obj1;
const obj3 = deepCopy(obj1);
console.log(obj3)
