js5-write-a-program-to-reverse-a-number.js

function reverseNumber(num) {
    let rev = 0;
    while (num > 0) {
        rev = rev * 10 + (num % 10);
        num = Math.floor(num / 10);
    }
    return rev;
}
console.log(reverseNumber(12345)); // Output: 54321
console.log(reverseNumber(9873)); // Output: 3789