how to find certain key by its value into mixed objects array?-CodePudding

const items = [ { 'first': [205, 208, 222] }, { 'second': 205 } ]

I need to find keys by all coincidence into its value/values

example:

find key by id=205, output: 'first', 'second'

find key by id=208, output: 'first'

CodePudding user response：

You can do something like this

const items = [ { 'first': [205, 208, 222] }, { 'second': 205 } ]


const findKey = (data, value) => data.reduce((res, item) => {
  let [[key, v]] = Object.entries(item)
  v = Array.isArray(v)?v: [v]
  if(v.includes(value)){
    return [...res, key]
  }
  return res
}, [])

console.log(findKey(items, 205))
console.log(findKey(items, 208))

CodePudding user response：

You can try getting the arrays of keys and values, then filter the keys and check if the corresponding index in values contain the variable id.

const items = [ { 'first': [205, 208, 222] }, { 'second': 205 } ]
const id = 205;
let keys = items.map(item => Object.keys(item)[0]);
let values = items.map(item => Object.values(item)[0]);

let output = keys.filter((_, index) => (values[index] == id || (typeof(values[index]) == 'object' && values[index].includes(id))));
console.log(output)

CodePudding user response：

You can click on 'Run code snippet' and see the output as mentioned in the question

const items = [{
    first: [205, 208, 222],
  },
  {
    second: 205,
  },
];

const toFind = 205;

const fin = items.reduce((finalOutput, item) => {
  let key = Object.keys(item)[0];
  if (Array.isArray(item[key])) {
    if (item[key].includes(toFind)) finalOutput.push(key);
  } else if (item[key] === toFind) {
    finalOutput.push(key);
  }
  return finalOutput;
}, []);

console.log(fin);

CodePudding user response：

Format your items data properly, then:

const items = [ { 'first': [205, 208, 201] }, { 'second': [205] } ]

const findKeys = n => items.reduce((acc, obj) => 
    Object.values(obj).some(arr => arr.includes(n)) ? 
        acc.concat(Object.keys(obj)) : 
        acc, 
    [])

const res = findKeys(208)

// Output: ['first']
console.log(res)