数据各种去重复，合并方法

1，数组对象去重通过id

function reduce(arr) {
  var obj = {};
  arr = arr.reduce(function (item, next) {
    obj[next.id] ? "" : (obj[next.id] = true && item.push(next));
    return item;
  }, []);
  return arr;
}

合并对象数据深度

function deepMerge(obj1, obj2) {
  let key;
  for (key in obj2) {
    obj1[key] =
      obj1[key] &&
      obj1[key].toString() === "[object Object]" &&
      obj2[key] &&
      obj2[key].toString() === "[object Object]"
        ? deepMerge(obj1[key], obj2[key])
        : (obj1[key] = obj2[key]);
  }
  return obj1;
}

3,深度复制拷贝数据

function judgeType(obj) {
    const toString = Object.prototype.toString;
    const map = {
      '[object Boolean]': 'boolean',
      '[object Number]': 'number',
      '[object String]': 'string',
      '[object Function]': 'function',
      '[object Array]': 'array',
      '[object Date]': 'date',
      '[object RegExp]': 'regExp',
      '[object Undefined]': 'undefined',
      '[object Null]': 'null',
      '[object Object]': 'object',
    };
    if (obj instanceof Element) {
      return 'element';
    }
    return map[toString.call(obj)];
  }
export function deepClone(data){
    const type = judgeType(data);
    let obj;
    if (type === 'array'){
    obj = [];
    } else if (type === 'object') {
    obj = {};
    } else {
// 不再具有下一层次
    return data;
    }
    if (type === 'array'){
    for (let i = 0, len = data.length; i < len; i++) {
        obj.push(deepClone(data[i]));
    }
    } else if (type === 'object') {
    // 对原型上的方法也拷贝了....
    for (const key in data) {
        obj[key] = deepClone(data[key]);
    }
    }
    return obj;
}