Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

JavaScript Recursion - Exercises, Practice, Solution

JavaScript Recursion [9 exercises with solution]

[An editor is available at the bottom of the page to write and execute the scripts.]

Use recursion to solve the following exercises.

1. Write a JavaScript program to calculate the factorial of a number. Go to the editor
In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120
Click me to see the solution

2. Write a JavaScript program to find the greatest common divisor (gcd) of two positive numbers. Go to the editor
Click me to see the solution.

3. Write a JavaScript program to get the integers in range (x, y). Go to the editor
Example : range(2, 9)
Expected Output : [3, 4, 5, 6, 7, 8]
Click me to see the solution.

4. Write a JavaScript program to compute the sum of an array of integers. Go to the editor
Example : var array = [1, 2, 3, 4, 5, 6]
Expected Output : 21
Click me to see the solution.

5. Write a JavaScript program to compute the exponent of a number. Go to the editor
Note : The exponent of a number says how many times the base number is used as a factor.
82 = 8 x 8 = 64. Here 8 is the base and 2 is the exponent.
Click me to see the solution.

6. Write a JavaScript program to get the first n Fibonacci numbers. Go to the editor
Note : The Fibonacci Sequence is the series of numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, . . . Each subsequent number is the sum of the previous two.
Click me to see the solution.

7. Write a JavaScript program to check whether a number is even or not. Go to the editor
Click me to see the solution.

8. Write a JavaScript program for binary search. Go to the editor
Sample array : [0,1,2,3,4,5,6]
console.log(l.br_search(5)) will return '5'
Click me to see the solution.

9. Write a merge sort program in JavaScript. Go to the editor
Sample array : [34,7,23,32,5,62]
Sample output : [5, 7, 23, 32, 34, 62]
Click me to see the solution.

More to Come !

* To run the code mouse over on Result panel and click on 'RERUN' button.*

Live Demo:

See the Pen javascript-common-editor by w3resource (@w3resource) on CodePen.


Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.



JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04