I have a simple fizzbuzz here:

```
var num = 1;

while (num <= 20) {
    switch(true){
        case(num%3 === 0 && num%5 === 0):
            console.log('fizzbuzz');
            break;
        case(num%3 === 0):
            console.log('fizz');
            break;
        case(num%5 === 0):
            console.log('buzz');
            break;
        default:
            console.log(num);
    }
    num++;
}

```

What is the meaning of the comparison to `0` after the modulus in this line: `num%3===0`?

Why isn't it just `num%3`?