How do you write a c program which accepts a positive integer and displays the number of digits?

Answer 1

#include
#include

void main()
{
unsigned long int num;
int i=0;
clrscr();
printf("Enter the digit\n");
scanf("%lu",&num);
while(num!=0)
{
num=num/10;
++i;
}
printf("Length=%d",i);
getch();
}

Answer 2

There are two ways. The naive way is to convert the number to a string by inserting it into a stringstream object and returning the size of the resultant string. A more efficient method is to repeatedly divide the number by 10 until the result is zero. The number of divisions gives the count of digits.

Answer 3

#include<stdio.h>

unsigned count_digits (unsigned num) {

unsigned sum;

sum = 1;

while (num /= 10) ++sum;

return sum;

}

int main (void ) {

unsigned num;

printf ("Enter a positive integer: ");

scanf ("%d", num);

printf ("There are %d digits in the number %d\n", count_digits (num), num);

return 0;

}

Answer 4

I suggest to convert it to a String, then use the String method to count the number of characters.