73rdProgram_Functions_2.cpp

/****************************************************************
 * Reverse of a number using Functions :-
 * 
 * ****************************************************************/

#include <iostream>
using namespace std;
int countDigits(int);     // function declaration
int reverse(int, int);    // function declaration
int main(){
    int num;
    cout << "Enter a number:" << "\n";
    cin >> num;
    int rev = reverse(num, countDigits(num));
    cout << "Reverse of the number is:" << rev << "\n";
    return 0;

}
int countDigits(int i)
{
    int s = 0;
    while (i != 0)
    {
        // a = a%10(is un-necessary just for showing mod op)
        i = i / 10;
        s = s + 1;
    }
    return s;
}
int reverse(int num, int s)
{
    int digit;
    int rev = 0;
    for (int i = 1; i <= s; i++)
    {
        digit = num % 10;
        rev = rev * 10 + digit;
        num = num / 10;
    }
    return rev;
}