By Vishal Basumatary in javascript — Mar 25, 2023

Update array with new object JavaScript without using index

As a web developer, I have come across situations where I need to update an array with a new object in JavaScript without using the index. In such cases, I found two ways to achieve this.

Using Spread Operator

The first way to update an array with a new object in JavaScript without using the index is by using the spread operator. The spread operator allows us to spread the existing array into a new array and add the new object at the end of it.


const array = [{id: 1, name: 'John'}, {id: 2, name: 'Jane'}];
const newObj = {id: 3, name: 'Jack'};

const newArray = [...array, newObj];

console.log(newArray); // [{id: 1, name: 'John'}, {id: 2, name: 'Jane'}, {id: 3, name: 'Jack'}]

In the above example, we have an existing array of objects called 'array'. We want to add a new object called 'newObj' to this array without using the index. We use the spread operator to spread the 'array' into a new array called 'newArray' and add the 'newObj' at the end of it. The output will be the updated array with the new object.

Using Concat Method

The second way to update an array with a new object in JavaScript without using the index is by using the concat method. The concat method allows us to concatenate two arrays into a new array.


const array = [{id: 1, name: 'John'}, {id: 2, name: 'Jane'}];
const newObj = {id: 3, name: 'Jack'};

const newArray = array.concat(newObj);

console.log(newArray); // [{id: 1, name: 'John'}, {id: 2, name: 'Jane'}, {id: 3, name: 'Jack'}]

In the above example, we have an existing array of objects called 'array'. We want to add a new object called 'newObj' to this array without using the index. We use the concat method to concatenate the 'array' and 'newObj' into a new array called 'newArray'. The output will be the updated array with the new object.

These are the two ways I found to update an array with a new object in JavaScript without using the index. Both methods are equally efficient and easy to use. It depends on the developer's preference which method they want to use.