Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Checking for special numbers in JavaScript
Problem
We are required to write a JavaScript function that takes in a number, num, as the first and the only argument.
Our function should return true if the sum of the digits of the number num is a palindrome number, false otherwise.
For example, if the input to the function is −
const num = 781296;
Then the output should be −
const output = true;
Output Explanation
Because the digit sum of 781296 is 33 which is a palindrome number.
Example
Following is the code −
const num = 781296;
const findSum = (num, sum = 0) => {
if(num){
return findSum(Math.floor(num / 10), sum + (num % 10));
};
return sum;
};
const palindromeDigitSum = (num = 1) => {
const sum = findSum(num);
const str = String(sum);
const arr = str.split('');
const reversed = arr.reverse();
const revNum = +arr.join('');
return revNum === sum;
};
console.log(palindromeDigitSum(num));Output
Following is the console output−
true
Updated on: 21-Apr-2021
309 Views
Advertisements