How to truncate an array in JavaScript ?

In JavaScript, there are two ways of truncating an array. One of them is using length property and the other one is using splice() method. In this article, we will see, how we can truncate an array in JavaScript using these methods.

• JavaScript length Property
• JavaScript splice() Method
• Javascript slice() Method

Using array.length property: Using Javascript`s array.length property, you can alter the length of the array. It helps you to decide the length up to which you want the array elements to appear in the output.

Syntax:

// n = number of elements you want to print
var_name.length = n;

In the above syntax, you can assign the size to the array using the array.length property according to the required output.

Example: In this example, we will see the basic use of Javascript`s array.length property.

Javascript

const num = [1, 2, 3, 4, 5, 6];
num.length = 3;
console.log(num);

Output:

[1, 2, 3]

As you can see in the above output, only three elements get printed. Assigning a value to the array.length property truncates the array and only the first n values exist after the program.

Using splice() Method: The splice() method removes items from an array, and returns the removed items.

Syntax:

// n=number of elements you want to print
var_name.splice(n); 

Example: In this example, we will see the truncating of an array using Javascript`s array.splice method.

Javascript

const num = [1, 2, 3, 4, 5, 6];
num.splice(4);
console.log(num);

Output:

[1, 2, 3, 4]

Using slice() Method: The Javascript arr.slice() method returns a new array containing a portion of the array on which it is implemented. The original remains unchanged.

Syntax:

arr.slice(begin, end)

Example: In this example, we will see the use of the slice() method.

Javascript

let arr = ["Geeksforgeeks", "Geek", "GFG", "gfg","G"];
arr = arr.slice(0, 2);
console.log(arr);

Output:

[ 'Geeksforgeeks', 'Geek' ]