我有两个对象，如果两个道具具有相同的键，我需要合并它们并连接字符串

Question

我有两个对象，如果两个道具具有相同的键，我需要合并它们并连接字符串 注意：我正在使用 lodash.js

obj1 = {
  name: 'john', 
  address: 'cairo'
}

obj2 = {
  num : '1', 
  address: 'egypt'
}

我需要合并的对象如下：

merged = {name:"john", num: "1", address:"cairo,Egypt"}

当我尝试使用时，地址属性的问题 _.defaults(obj1,obj2) 或者 _.merge(obj1,obj2)

地址值将是 obj2 内的地址 prop 的值 所以我需要一种方法来合并两个对象并连接每个对象中的两个地址道具。

Answer 1

试试这个：

    function merge(obj1, obj2) {
      let merged = {
        ...obj1,
        ...obj2
      };
      Object.keys(obj1).filter(k => obj2.hasOwnProperty(k)).forEach((k) => {
        merged[k] = obj1[k] + "," + obj2[k]
      })
      return merged
    }

    obj1 = {
      name: 'john',
      address: 'cairo'
    }

    obj2 = {
      num: '1',
      address: 'egypt'
    }

    console.log(merge(obj1, obj2))

Answer 2

您甚至不需要 lodash。您可以轻松地为此创建自己的函数。您可以这样做：

• new Set - 查找两个输入对象中所有唯一的键
• for...of - 迭代唯一的上面计算出的键

function mergeObjects(obj1, obj2) {
  let merged = {};
  for (const property of [...new Set([...Object.keys(obj1),...Object.keys(obj2)])]) {
    if(obj1[property]) merged[property] = obj1[property];
    if(obj2[property]) merged[property] = merged[property] ? `${merged[property]},${obj2[property]}` : obj2[property];
  }
  return merged;
}

const obj1 = { name: 'john', address: 'cairo' };
const obj2 = { num : '1', address: 'egypt' };

const mergedObj = mergeObjects(obj1, obj2);
console.log(mergedObj);

Answer 3

function mergeObjects(objArr) {
    const newObj = {};

    objArr.forEach((element) => {
        const keys = Object.keys(element);
        keys.forEach((key) => {
            if (newObj[key]) newObj[key] = newObj[key] + "," + element[key];
            else newObj[key] = element[key];
        });
    });
    return newObj;
}

const obj1 = {name: 'john',   address: 'cairo'}

const obj2 = {  num : '1',   address: 'egypt'}
console.log(mergeObjects([obj1, obj2]));

这样您就可以合并任意数量的对象！

Answer 4

您可以使用 _.mergeWith() 将特定键的值连接到数组，然后使用 _.mapValues() 将数组连接到字符串：

const { mergeWith, mapValues, uniq, join } = _;

const fn = (predicate, ...objs) => mapValues(
  // merge the objects
  mergeWith(
    {}, 
    ...objs, 
    // handle the keys that you want to merge in a uniqe way
    (a = [], b = [], key) => predicate(key) ? a.concat(b) : undefined
  ),
  // transform the relevant keys' values to a uniqe strings
  (v, key) => predicate(key) ? uniq(v).join(', ') : v
);

const obj1 = { name: 'john', address: 'cairo' };
const obj2 = { num : '1', address: 'egypt' };

const result = fn(key => key === 'address', obj1, obj2);

console.log(result);

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