JavaScript对象拷贝_深拷贝实现方案

const obj = { a: 1, b: { c: 2 } };
const copied = JSON.parse(JSON.stringify(obj));
obj.b.c = 3;
console.log(copied.b.c); // 输出 2，说明已深拷贝

function deepClone(obj, cache = new WeakMap()) {
  if (obj === null || typeof obj !== 'object') return obj;
  if (cache.has(obj)) return cache.get(obj); // 防止循环引用

  let clone;
  if (obj instanceof Date) {
    clone = new Date(obj);
  } else if (obj instanceof RegExp) {
    clone = new RegExp(obj);
  } else if (Array.isArray(obj)) {
    clone = obj.map(item => deepClone(item, cache));
  } else {
    clone = {};
    for (let key in obj) {
      if (obj.hasOwnProperty(key)) {
        clone[key] = deepClone(obj[key], cache);
      }
    }
  }

  cache.set(obj, clone);
  return clone;
}

function structuredClone(obj) {
  return new Promise(resolve => {
    const { port1, port2 } = new MessageChannel();
    port2.onmessage = e => resolve(e.data);
    port1.postMessage(obj);
  }).then(data => data);
}
// 注意：该方法是异步的

const _ = require('lodash');
const obj = { a: { b: 1 } };
const copied = _.cloneDeep(obj);