In this article, we will learn how to remove the last n elements from the end of the given array in JavaScript.
We can remove n elements from the end of a given array in the following ways:
- Using splice() Method
- Using pop() Method
- Using filter() Method
- Using Array slice() method
- Using while loop
Method 1: Using splice() Method
It is used to modify an array by adding or removing elements from it. This method accepts the index from which the modification has to be made and the number of elements to delete. The index from which the deletion has to start can be found by subtracting the number of elements from the length of the array.
Syntax:
array.splice(start, deleteCount);
Example: In this example, we will be using the Javascript splice() method to remove the elements from the end of a given array.
Javascript
// Define the arraylet arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];console.log("Original Array:", arr);// Define the number of elements to removelet elemsToDelete = 3;// Using the splice() method to remove from// the last nth index for n elementsarr.splice(arr.length - elemsToDelete, elemsToDelete);console.log("Modified Array:", arr); |
Original Array: [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ] Modified Array: [ 1, 2, 3, 4, 5, 6 ]
Method 2: Using pop() Method
It is used to remove the last element from the array. This can be repeated in a loop of n iterations to remove the last n elements of the array using the while loop.
Syntax:
array.pop();
Example: In this example, we will be using the Javascript pop() method to remove the elements from the end of a given array.
Javascript
// Define the arraylet arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];console.log("Original Array:", arr);// Define the number of elements to removelet elemsToDelete = 5;// Loop for the number of elements// to deletewhile (elemsToDelete--) // Pop the last element from the // end of the array arr.pop();console.log("Modified Array:", arr); |
Original Array: [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ] Modified Array: [ 1, 2, 3, 4 ]
Method 3: Using filter() Method
It is used to filter the array and apply the callback function to each item of the array and filter the element which returns true against the callback function.
Syntax:
Array.filter( callback )
Example: In this example, we will be using the Javascript filter() method to remove the elements from the end of a given array.
Javascript
// Define the arraylet arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];console.log("Original Array:", arr);// Define the number of elements to removelet elemsToDelete = 5;// Loop for the number of elements// to deletelet k = arr.filter((x, i) => i + elemsToDelete < arr.length)// Pop the last element from the// end of the arrayconsole.log("Modified Array:", k); |
Original Array: [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ] Modified Array: [ 1, 2, 3, 4 ]
Method 4: Using Array slice() method
This 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:
Javascript
const arr = [1, 2, 3, 4, 5, 6];const withoutLast = arr.slice(0, -1);//orignal arrayconsole.log(arr);//Modified arrayconsole.log(withoutLast); |
[ 1, 2, 3, 4, 5, 6 ] [ 1, 2, 3, 4, 5 ]
Method 5: Using while loop
By using the while loop we can iterate over the array and we will use pop() method for removing the element from the end.
Example:
Javascript
const arr = [1, 2, 3, 4, 5, 6];//remove the last 3 elements from an arraylet n = 3;while (n > 0) { n -= 1; arr.pop();}console.log(arr); |
[ 1, 2, 3 ]
