js 手写深比较、深拷贝

 深度比较

function isObject(obj) {
  return typeof obj === 'object' && obj !== null
}
function isEqual(obj1, obj2) {
  if (!isObject(obj1) || !isObject(obj2)) {
    return obj1 === obj2;
  }

  if (obj1 === obj2) {
    return true;
  }

  let obj1keys = Object.keys(obj1);
  let obj2keys = Object.keys(obj2);

  if (obj1keys.length !== obj2keys.length) {
    return false;
  }

  for(let k in obj1) {
    const res = isEqual(obj1[k], obj2[k]);
    if (!res) {
      return false
    }
  }
  return true;
}

 深拷贝

function deepClone(data) {
  if (typeof data === 'object') {
    let result;
    if (data instanceof Array) {
      result = [];
    } else {
      result = {};
    }
    for(let key in data) {
      // 保证key 不是原型的属性
      if (data.hasOwnProperty(key)) {
        if (typeof data[key] !== 'object') {
          result[key] = data[key];
        } else {
          result[key] = deepClone(data[key]);
        }
      }
    }
    return result;
  } else {
    return data;
  }
}