# Need help: Leap-Year project

Hey, I’ve been interested in C++ for a long time now and started using this service to learn it but now I’m stuck on this exercise. Not sure if my math is wrong or the output is . (I also used this resource to further assist me on the math, https://docs.microsoft.com/en-us/office/troubleshoot/excel/determine-a-leap-year ) Thanks to anyone who’s willing to help. Edit: I added the second else if just for “making sure” purposes although It’s probably unnecessary.

Here’s code:

``````#include <iostream>

int main() {
// Variables
int y;

// Store input Data
std::cout << "Enter year: ";
std::cin >> y;

// Calculation

if (y < 1000 or y > 9999) {

// Testifies if year is four-digit
std::cout << "Invalid Year.\n";

} else if (y / 4 == 0 and y / 100 == 0 and y / 400 == 0) {

// if y is divisible by 4, 100 and 400, then it's a year leap.
std::cout << y;
std::cout << " falls on a leap year.\n";

} else if (y / 4 == 0 and y / 100 != 0) {

// if y is divisble by 4 and not 100 then it's a year leap.
std::cout << y;
std::cout << " falls on a leap year.\n";

} else {
// else it isn't a year leap.
std::cout << y;
std::cout << " isn't a leap year.\n";

}
}
``````

Hello @system8222641569, welcome to the forums! Are you sure you want to use the `/` operator (divided by). Shouldn’t you use the modulo operator?

What is the modulo operator, and what does it do?

The modulo operator is used in similar fashion to the `/` operator, however returns the remainder of the division. So, if I have `5 modulo 4`, it should return `1`, as `5 divided by 4` equals `1 remainder 1`.

This is the modulo operator: `%`

Aside, why do you need this line:

if this line will also do:

It seems like you have the condition `if the year is divisible by 4, and by 100, and by 400, then do the following code:`. But since `100` and `400` are both divisible by `4`, why do you need them in the condition at all?

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Ah! Thank you! @codeneutrino, I used the wrong operation, should’ve been using this " % " instead of this " / ". Also, I added that line for the sake of my own sanity, I kept peeping at forums with this exercise, but they had more serious questions then mine, I feel dumb now. Ha, well, thanks for your help. (For some reason, I already suspected that was the issue, but my brain-cells were dead at that moment so I didn’t want to think much about it). Have a good day, and thank you for the warm welcome too.

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