C-Plus-Plus/math/finding_number_of_Digits_in_a_Number.cpp

/**
 * @author [ANSHUMAAN](https://github.com/amino19)
 * @file [Program to count digits in an
 * integer](https://www.geeksforgeeks.org/program-count-digits-integer-3-different-methods)
 *
 * \brief Finding number of Digits in a Number
 * \details It is a very basic math of finding
 *  number of digits in a given number i.e, we
 *  can use it by inputting values whether it
 *  can be a positive/negatie value, lets say
 *  integer.
 *  For more details, refer Algorithms-Explanation
 */

#include <cassert>   /// for assert
#include <iostream>  /// for IO operations

/**
 * @brief Main function
 * @returns 0 on exit
 */
int main(void) {
    /* Initialize 'n' & 'count' by 0 */
    int n = 0;
    int count = 0;
    std::cout << "Enter an integer: ";
    std::cin >> n;
    /* iterate until n becomes 0
     *  remove last digit from n in each iteration
     *  increase count by 1 in each iteration */
    while (n != 0) {
        /* we can also use: n = n/10 */
        n /= 10;
        /*  each time while loop running, count will
         *  be increment by 1.
         */
        ++count;
    }
    std::cout << "Number of digits: " << count;
}