Javascript: how to create an object with numeric String keys

Question

I need to create an object in javascript, similar to the following structure:

{ 
  '1': { 
    'key1-1': 'val1-1',
    'key-1-2': 'val1-2'
  }, 
  '2': { 
    'key1-1': 'val1-1',
    'key1-2': 'val1-2'
  }
}

I tried with Object(); but the key remains the literal name of the variable.

> var myObj = new Object();
> for (var i  = 1; i< 5; i++) {
... myObj.i = {'key1-1': 'val1-1',
.....         'key-1-2': 'val1-2'}
... }
> console.log(myObj)
{ i: { 'key1-1': 'val1-1', 'key-1-2': 'val1-2' } }

Tried converting the variable i to string but still the same.

> for (var i  = 1; i< 5; i++) {
... var iStr = i.toString();
... myObj.iStr = {'key1-1': 'val1-1',
..... 'key-1-2': 'val1-2'}
... }
> console.log(myObj)
{ iStr: { 'key1-1': 'val1-1', 'key-1-2': 'val1-2' } }

How can we create a json Object with numeric string keys like '1', '2', '3' ...

The string conversion happens automatically. Even array indexes are strings. You are using the wrong syntax to define the key. — Aluan Haddad
– Aluan Haddad, Commented Sep 23, 2018 at 9:29
There is no such thing as a json Object. You want an object? Then it's Javascript. You want a string representation of that object? Then it's JSON. — connexo
– connexo, Commented Sep 23, 2018 at 9:31

amrender singh · Accepted Answer · 2018-09-23 09:36:45Z

1

You can use two nested for loops along with template literals to make it more generic. And use the bracket notation for creating dynamic properties.

let m = 3;
let n =2;

let result = {};

for(let i = 1; i <=m; i++){
  result[i] = {};
  for(let j = 1; j <=n; j++){
      result[i][`key1-${j}`] = `val1-${j}`;
  }
}
console.log(result);

edited Sep 23, 2018 at 9:36

answered Sep 23, 2018 at 9:31

amrender singh

8,2594 gold badges27 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Shubham Gupta · Accepted Answer · 2018-09-23 09:29:59Z

0

Change myObj.istr to myObj[istr]

answered Sep 23, 2018 at 9:29

Shubham Gupta

2,6461 gold badge10 silver badges19 bronze badges

Comments

Terry D · Accepted Answer · 2018-09-23 09:32:22Z

0

https://www.w3schools.com/js/js_object_properties.asp

Another option is use :

myObj[istr] = value

Where istr is a string

answered Sep 23, 2018 at 9:32

Terry D

3693 silver badges15 bronze badges

Collectives™ on Stack Overflow

Javascript: how to create an object with numeric String keys

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related