Group Object based on ending Number

Question

Here is the sample object

{
  abc_0: 'a',
  bcd_0: 'b',
  cde_0: 'c',
  abc_1: 'a',
  bcd_1: 'b',
  cde_1: 'c',
  def_1: 'd',

}

I want to group via the number they end with and wante the expected output to be

{
 0: {abc: 'a', bcd: 'b', cde: 'c'},
 1: {abc: 'a', bcd: 'b', cde: 'c', def : 'd'},
}

Familiarize yourself with [how to access and process nested objects, arrays or JSON](/q/11922383/4642212) and how to [create objects](//developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/Object_initializer) and use the available static and instance methods of [`Object`](//developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object#Static_methods) and [`Array`](//developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array#Static_methods). — Sebastian Simon, Dec 08 '21 at 08:58

Hao Wu · Accepted Answer · 2021-12-08T09:12:28.557

5

You may try this solution:

const data = {
  abc_0: 'a',
  bcd_0: 'b',
  cde_0: 'c',
  abc_1: 'a',
  bcd_1: 'b',
  cde_1: 'c',
  def_1: 'd',
};

const result = Object.entries(data).reduce((acc, [combo, value]) => {
  const [key, index] = combo.split('_');
  acc[index] = { ...acc[index], [key]: value };
  return acc;
}, {});

console.log(result);

edited Dec 08 '21 at 09:12

answered Dec 08 '21 at 09:04

Hao Wu

17,573
6
28
60

Ran Turner · Answer 2 · 2022-04-21T11:36:52.320

You can write something like this to achieve it

const obj = {
  abc_0: 'a',
  bcd_0: 'b',
  cde_0: 'c',
  abc_1: 'a',
  bcd_1: 'b',
  cde_1: 'c',
  def_1: 'd',

};

const groupByChar = () => {
  const res = {};
  for (let k in obj){
    const char = k.charAt(k.length-1);
    if (!res[char]){
      res[char] = {};
    }

    const key = k.substring(0, k.length - 2);

    res[char][key] = obj[k];
  }
  
  return res;
}

const res = groupByChar();


console.log(res);

score 1 · Answer 3 · answered Dec 08 '21 at 10:38

I deliberately disrupted the data sequence to better meet your needs.

const data = {
  abc_0: 'a',
  abc_1: 'a',
  bcd_0: 'b',
  bcd_1: 'b',
  cde_0: 'c',
  cde_1: 'c',
  def_0: 'd',
  def_1: 'd',
};

const res = Object.keys(data)
  .map((key) => {
    const [char, num] = key.split('_');
    return {
      [num]: {
        [char]: data[key],
      },
    };
  })
  .reduce((acc, cur) => {
    const acc_keys = Object.keys(acc);
    const [cur_key] = Object.keys(cur);
    if (acc_keys.includes(cur_key)) {
      acc[cur_key] = { ...acc[cur_key], ...cur[cur_key] };
      return {
        ...acc,
      };
    } else {
      return { ...acc, ...cur };
    }
  }, {});

console.log(res);

score 1 · Answer 4 · answered Dec 08 '21 at 14:20

Another way of writing it

const obj= {
    abc_0: 'a',
    bcd_0: 'b',
    cde_0: 'c',
    abc_1: 'a',
    bcd_1: 'b',
    cde_1: 'c',
    def_1: 'd',
  }

const filtered = Object.keys(obj).map((el)=>el.split('_')[1]).filter((el, i)=>Object.keys(obj).map((el)=>el.split('_')[1]).indexOf(el)===i);

const res = Object.entries(obj).reduce((acc, curr, i)=>{
    const left=curr[0].split('_')[0]  
    const right=curr[0].split('_')[1]        
    filtered.forEach((index)=>{
        if(right==index){    
            !acc[index]? acc[index]={}:null
            !acc[index][left]?acc[index][left]=obj[`${left}_${right}`]:null
        }
    }) 
    return acc
},{})

console.log(res);

Group Object based on ending Number

4 Answers4