比较对象内的键值以进行重复更新 [英] Compare key values within object for duplicate updated

问题描述

这是来自将对象内键值重复进行比较的后续帖子获得后续答案.

This is a follow up post from Compare key values within object for duplicate for a follow up answer.

我有一个对象:

myObj = {
  attendent-0-id:"123",
  attendent-0-name:"Bob Smith",
  attendent-1-id:"1234",
  attendent-1-name:"Alex Smith",
  attendent-2-id:"123",
  attendent-2-name:"Charlie Smith",
  attendent-0-id:"123",
  attendent-0-name:"John Smith",
  attendent-maxGuest:1,
  attendent-party-name:"",
}

感谢您的帮助(Rick)，我能够90％地到达那里.

Thanks to help on here (Rick) I was able to get 90% of the way there.

function errorOnDuplicateIds(obj) {
  const map = {};
  const pattern = /^attendent-\d+-id$/;

  for (const key of Object.keys(obj)) {
    if (pattern.test(key)) {      
      const value = obj[key]

      if (value in map) {
        map[value] = [map[value], key];       
      } else {
        map[value] = key
      }
    }    
  }
return map;
}

我得到了以下回报:

array:[
  0:(2) ["attendent-0-name", "attendent-1-name"]
  1:"attendent-2-name"
]

但我正在寻找:

array:[
  0:(2) ["attendent-0-name", "attendent-1-name", "attendent-2-name"]
]

我遇到的问题是，如果有两个匹配的键，这是可行的，但如果有三个或三个以上，它将不起作用(正确).

The issue I am having is that while this works if there are two matching keys it will not work (Correctly) if there are three or more.

推荐答案

如果要为映射中的每个键提供所有匹配项的数组，则需要在首次找到键时从设置数组开始.在随后的比赛中，只需将其推入该数组即可:

If you want to have an array of all matches for each key in you map, you need to start by setting an array when you find a key the first time. On subsequent matches, just push into that array:

const myObj = {'attendent-0-id': "1234",'attendent-0-name': "Bob Smith",'attendent-1-id': "123",'attendent-1-name': "Alex Smith",'attendent-2-id': "123",'attendent-2-name': "Charlie Smith",'attendent-maxGuest': 1,'attendent-party-name': "",};
  
function errorOnDuplicateIds(obj) {
  const map = {};
  const pattern = /^attendent-\d+-id$/;

  for (const key of Object.keys(obj)) {
    if (pattern.test(key)) {
      const value = obj[key]

      if (value in map) {
        map[value].push(key); // push a new value 
      } else {
        map[value] = [key] // set it to an array
      }
    }
  }

  /* if you only want lengths > 1
     otherwise just return map   */
  let filtered = Object.entries(map)
    .reduce((a, [key, value]) =>  value.length > 1 ? Object.assign(a, {[key]: value}) : a, {})

  return filtered;
}

console.log(errorOnDuplicateIds(myObj));

如果您只对命中次数多的值感兴趣，则可以reduce()向下查找只有长度大于1的值的地图，这就是摘要中的最后一位.

If you are only interested in values with more than one hit, you can reduce() down to a map with only values of length greater than one, which is what the last bit in the snippet does.

这篇关于比较对象内的键值以进行重复更新的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！