How to convert array of object to desired object in javascript

Question

I want to convert array of object to a desired format in javascript, Please help me to resolve this.

const obj = [
  {name: 'parry1', age:22, height:5},
  {name: 'parry 2', age:23, height:6},
  {name: 'parry3', age:24, height:7}
]

// output = {name:['parry1', 'parry 2', 'parry3'], age:[22, 23, 24], height:[5, 6, 7]}

Ok, we can help, but, where is the code you are using to try to solve this? — Calvin Nunes, Sep 23 '19 at 12:20

Adnane Ar · Answer 1 · 2019-09-23T12:30:10.240

Hope this helps you !

const obj = [
  {name: 'parry1', age:22, height:5},
  {name: 'parry 2', age:23, height:6},
  {name: 'parry3', age:24, height:7}
];

function ArrayToObject(array){
  const newObj={
    name: [],
    age: [],
    height: []
  };
  array.forEach(function(row){
    newObj.name.push(row["name"]);
    newObj.age.push(row["age"]);
    newObj.height.push(row["height"]);
  });
  return newObj;
}

console.log( ArrayToObject(obj) );

output = {name:['parry1', 'parry 2', 'parry3'], age:[22, 23, 24], height:[5, 6, 7]}

score 1 · Answer 2 · answered Sep 23 '19 at 12:31

This is a good use case for the zip function:

let zip = (...a) => a[0].map((_, i) => a.map(b => b[i]))

const obj = [
    {name: 'parry1', age: 22, height: 5},
    {name: 'parry 2', age: 23, height: 6},
    {name: 'parry3', age: 24, height: 7}
]

res = Object.fromEntries(
    zip(
        Object.keys(obj[0]),
        zip(...obj.map(Object.values))
    ));


console.log(res)

score 0 · Accepted Answer · answered Sep 23 '19 at 12:31

You could map your array to the entries of your object (using .map), and then use .forEach with .reduce() to build an object which has each key from your objects in your array with the values being arrays populated with their respective value:

const arr = [{name: 'parry1', age:22, height:5}, {name: 'parry 2', age:23, height:6}, {name: 'parry3', age:24, height:7}];

const res = arr.map(Object.entries).reduce((acc, entries) => {
  entries.forEach(([k, v]) => {
    acc[k] = [...(acc[k] || []), v];
  });
  return acc;
}, {});

console.log(res);

score 0 · Answer 4 · answered Sep 23 '19 at 12:32

You could take the entries and return an object with all keys as arrays with their values.

var array = [{ name: 'parry1', age: 22, height: 5 }, { name: 'parry 2', age: 23, height: 6 }, { name: 'parry3', age: 24, height: 7 }],
    result = array.reduce((r, o) => Object.entries(o).reduce((q, [k, v]) => {
        q[k] = q[k] || [];
        q[k].push(v);
        return q;
    }, r), {});

console.log(result);

score 0 · Answer 5 · answered Sep 23 '19 at 12:35

Try this.

const obj = [
  {name: 'parry1', age:22, height:5},
  {name: 'parry 2', age:23, height:6},
  {name: 'parry3', age:24, height:7}
]

let output = {};

obj.forEach((o) => {
  Object.keys(o).forEach((prop) => {
    if (output[prop] === undefined) {
      output[prop] = [];
    }

    output[prop].push(o[prop]);
  });
})

console.log(output);

score 0 · Answer 6 · answered Sep 23 '19 at 13:32

Loop through the original array. For each row, check if there is a corresponding field in the resObj. If no, then create the field. Push the value into this field.

Code -

const obj = [
  {name: 'parry1', age:22, height:5},
  {name: 'parry 2', age:23, height:6},
  {name: 'parry3', age:24, height:7}
]

function arrayToObj(arr) {
  let resObj={};
  arr.forEach(row=> {
    Object.keys(row).forEach(key=>{
      if(!resObj[key]) {
        resObj[key]=[];
      }
      resObj[key].push(row[key]);
    })
  })
  return resObj;
}

console.log(JSON.stringify(arrayToObj(obj)));
// {"name":["parry1","parry 2","parry3"],"age":[22,23,24],"height":[5,6,7]}

How to convert array of object to desired object in javascript

6 Answers6