Question

Without using string manipulation (checking for an occurrence of the . or , character) by casting the product of an int calculation to string.

and

without using try / catch scenarios relying on errors from data types.

How do you specifically check using C# if a number is a multiple of another?

For example 6 is a multiple of 3, but 7 is not.

Answer 1

Try

public bool IsDivisible(int x, int n)
{
   return (x % n) == 0;
}

The modulus operator % returns the remainder after dividing x by n which will always be 0 if x is divisible by n.

For more information, see the % operator on MSDN.