Question

Write a program in c which counts for the number of digits in an integer number being entered by user using: do While loop

Answer 1

/*
 * If need use do ... while only
*/

#include <stdio.h>

void main()
{
    int num, digit = 0;

    printf("Input number: ");
    scanf("%d", &num);

    do
        digit += !!num;
    while (num /= 10);

    printf("Digits: %d\n", digit);
}