js clone object

const original = { a: 1, b: { c: 2 } };
const shallowCopy = { ...original };

// 修改浅拷贝的顶层属性
shallowCopy.a = 10;
console.log(original.a); // 1
console.log(shallowCopy.a); // 10

// 修改嵌套对象的属性
shallowCopy.b.c = 20;
console.log(original.b.c); // 20
console.log(shallowCopy.b.c); // 20

const original = { a: 1, b: { c: 2 } };
const deepCopy = JSON.parse(JSON.stringify(original));

// 修改深拷贝的顶层属性
deepCopy.a = 10;
console.log(original.a); // 1
console.log(deepCopy.a); // 10

// 修改嵌套对象的属性
deepCopy.b.c = 20;
console.log(original.b.c); // 2
console.log(deepCopy.b.c); // 20

function deepCopy(obj, hash = new WeakMap()) {
  if (Object(obj) !== obj) return obj; // 原始类型直接返回
  if (hash.has(obj)) return hash.get(obj); // 处理循环引用
  let result = Array.isArray(obj) ? [] : {};
  hash.set(obj, result);
  Reflect.ownKeys(obj).forEach(key => {
    result[key] = deepCopy(obj[key], hash);
  });
  return result;
}

const original = { a: 1 };
original.b = original;
const deepCopyObj = deepCopy(original);

function deepCopy(obj) {
  if (typeof obj !== 'object' || obj === null) return obj;
  let copy = Array.isArray(obj) ? [] : {};
  for (let key in obj) {
    if (obj.hasOwnProperty(key)) {
      copy[key] = (typeof obj[key] === 'object' && obj[key] !== null) ? deepCopy(obj[key]) : obj[key];
    }
  }
  return copy;
}

const original = { a: 1, b: new Date(), c: function() { console.log('hello'); } };
const deepCopyObj = deepCopy(original);