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cloopsdo-whiledigitsinteger-arithmetic

why n mod 10 in loop doesn't show output

I have solve a basic problem in c that is count the digits in integer and I have written -

#include<stdio.h>

int main()   
{
    int n;

    scanf("%d",&n);
    
    int i;
    while(n!=0)
    {
        n %= 10;
        ++i;
    }
    
    printf("%d",i);
}

I already know that above code is wrong, I should write n/=10; instead of n%=10; but I wants to know why it is not printing even value of i i.e 0.

If I have written any wrong so please ignore it ,I am new here..

Solution

  • If the number n is not divisible by 10 then the value of this expression (the remainder of the division)

    n %= 10;

    will never be equal to 0.

    Also the variable i is not initialized.

    int i;

    You should write

    int i = 0;

do
{
    ++i;
} while ( n /= 10 );

printf( "%d\n", i );