Arrays are used to store multiple elements in a single object.
You can get a subarray from an array in JavaScript using the array.slice() method.
Basic Example
var myArray = [1, 2, 3, 4, 5]; // Get a subarray with elements at indices 1 and 2 (inclusive)
var subArray = myArray.slice(1, 3);
console.log(myArray); // [1, 2, 3, 4, 5]
console.log(subArray); // [2, 3]- Creates a subarray from the elements in the range of the start and end indexes specified.
- Doesn’t mutate the original array
This tutorial teaches you how to create a subarray from an array in JavaScript.
Array.slice() method
The Array.slice() method creates a subarray based on the elements in the start and end index specified.
- It doesn’t mutate the original array.
- Creates a new shallow copy of the array.
Use this method when you want to create a subarray based on the range of index positions in the original array and don’t want to modify the original array.
Code
var myArray = [1, 2, 3, 4, 5]; // Get a subarray with elements at indices 1 and 2 (inclusive)
var subArray = myArray.slice(1, 3);
console.log(myArray); // [1, 2, 3, 4, 5] - Original array remains the same
console.log(subArray); // [2, 3] - New subarray is created with the elementsArray.splice() method
The Array.splice() method allows you to change the array by removing or replacing the original array.
- When you pass the
startindex and a number of elements to delete, it’ll remove the number of items starting from the index and returns a new array with those elements. - It mutates the original array.
Use this method when you want to remove some elements from the original array and create a sub-array from the removed elements.
Code
var myArray = [1, 2, 3, 4, 5]; // Get a subarray with elements at indices 1 and 2 (inclusive)
var subArray = myArray.splice(1, 3);
console.log(myArray); // [1, 5]
console.log(subArray); // [2, 3, 4]Array.filter() method
The Array.filter() method allows you to create a subarray based on a specific condition.
- Filters the items that pass the specific condition
- Returns a new array with the filtered elements. Doesn’t mutate the original array.
Use this method when you want to create a sub-array with elements that pass a specific condition.
Code
Use the following code to create an array with elements greater than 3.
var myArray = [1, 2, 3, 4, 5];
const subArray = myArray.filter(x => x >3);
console.log(subArray); // [4,5]