Add key-value pair to every object in array of objects in JavaScript

Sometimes, we’ve to add flag or some new key-value pair to every object in array of objects. For that we can follow three ways to achieve it.

For suppose, we have an array of objects as below and we want to add gender key to all the objects.

students = 
[
   {
      name: 'Radhika',
      age: 26,
    },
    {
      name: 'Radha',
      age: 24,
    },
    {
      name: 'Jyothi',
      age: 25,
    },
];
// Expected Output
students = 
[
    {
       name: 'Radhika',
       age: 26,
       gender: 'female'
    },
    {
       name: 'Radha',
       age: 24,
       gender: 'female'
   },
   {
       name: 'Jyothi',
       age: 25,
       gender: 'female'
    },
];

Method 1 — Using Map:

Method 2 — Using Filter :

Method 3 — Using ForEach :

Link for whole code : Stackblitz

Hope this helps 😀🫠

Originally published at

Add key-value pair to every object in array of objects in JavaScript