深克隆

deepClone.js

function deepCopy(target) {
  let copyed_objs = []; //此数组解决了循环引用和相同引用的问题，它存放已经递归到的目标对象
  function _deepCopy(target) {
    if (typeof target !== 'object' || !target) {
      return target;
    }
    for (let i = 0; i < copyed_objs.length; i++) {
      if (copyed_objs[i].target === target) {
        return copyed_objs[i].copyTarget;
      }
    }
    let obj = {};
    if (Array.isArray(target)) {
      obj = []; //处理target是数组的情况
    }
    copyed_objs.push({ target: target, copyTarget: obj });
    
    Object.keys(target).forEach((key) => {
      if (obj[key]) {
        return;
      }
      obj[key] = _deepCopy(target[key]);
    });
    return obj;
  }
  return _deepCopy(target);
}

// 测试代码
let obj = {
  a: 12,
  b: [123123, 123123],
  c: function() {
    let a = 0;
  },
  d: {
    a: { f: 'asdfasdf' },
    g: 1
  },
};
let b = deepCopy(obj);
console.log(obj);
console.log(b);