c - How to check if a int var contains a specific number

Question

How to check if a int var contains a specific number

I cant find a solution for this. For example: i need to check if the int 457 contains the number 5 somewhere.

Thanks for your help ;)

Answer 1

457 % 10 = 7    *

457 / 10 = 45

 45 % 10 = 5    *

 45 / 10 = 4

  4 % 10 = 4    *

  4 / 10 = 0    done

Get it?

Here's a C implementation of the algorithm that my answer implies. It will find any digit in any integer. It is essentially the exact same as Shakti Singh's answer except that it works for negative integers and stops as soon as the digit is found...

const int NUMBER = 457;         // This can be any integer
const int DIGIT_TO_FIND = 5;    // This can be any digit

int thisNumber = NUMBER >= 0 ? NUMBER : -NUMBER;    // ?: => Conditional Operator
int thisDigit;

while (thisNumber != 0)
{
    thisDigit = thisNumber % 10;    // Always equal to the last digit of thisNumber
    thisNumber = thisNumber / 10;   // Always equal to thisNumber with the last digit
                                    // chopped off, or 0 if thisNumber is less than 10
    if (thisDigit == DIGIT_TO_FIND)
    {
        printf("%d contains digit %d", NUMBER, DIGIT_TO_FIND);
        break;
    }
}