IF statement - Error: expression must have integral or unscoped enum type

[bulba5aur]

What am I doing wrong here?

#include <iostream>
using namespace std;

int main()
{
	for (double a = 600851475143 / 2; a > 0; a--)
	{
		if (a % 2 == 0)  //a is underlined red with the error
		{
			continue;
		}
	}
	return 0;
}

[Peter87]

You can't use the % operator on floating point types such as float or double.

[bulba5aur]

Okay thank you. Is there no way to use % with a number too large for long int?

[Peter87]

The % operator works with all integer types so it will work with long int just fine. If long int is not big enough you could try long long int instead.

[bulba5aur]

Very cool, I didn't know long long was a thing! I am really new to this... thanks again.