How to insert an item into array at specific index in JavaScript

Are you looking for a way to insert an item into an array at a specific index in JavaScript? If so, then this blog post is perfect for you!

In JavaScript, there are several ways to add items to arrays. One of the most common methods is using the splice() method. This method allows us to specify which index we want our new item inserted at and what elements should be removed from that position if any.

Syntax #

The splice() method takes three arguments.

myArray.splice(indexNumber, 0 , newItem);

1. The starting index at which to start changing the array.
2. The number of elements to remove from the array (0 in this case).
3. The elements to add to the array.

Here is an example that demonstrates how to insert a value at a specific index.

<script>
  let myArray = [1, 2, 4, 5]; // original array
  myArray.splice(2, 0, 3); // insert 3 at index 2
  console.log(myArray); // [1, 2, 3, 4, 5]
</script>

In this example, myArray.splice(2, 0, 3) inserts the value 3 at index 2 of the array myArray, and the output is [1, 2, 3, 4, 5]. Note that the first argument 2 specifies the index at which to start inserting, the second argument 0 specifies the number of elements to remove, and the third argument 3 specifies the value to insert.

We hope this tutorial has been helpful in understanding how easy it is to use the splice() method for adding items into arrays with specific indexes!