Checking the division remainder in JavaScript

Suppose we have two variables with numbers:

let a = 10;
let b = 3;

Let's find the remainder after dividing one variable by another:

let a = 10;
let b = 3;

console.log(a % b); // shows 1

Let now the variables store such values that one variable is divided by the second completely:

let a = 10;
let b = 5;

console.log(a % b); // shows 0

Let's write a script that will check if one number is divisible by the second:

let a = 10;
let b = 3;

if (a % b === 0) {
	console.log('is divisible');
} else {
	console.log('is divided with a remainder');
}

Let now it is required, if the number is divided with the remainder, output this remainder to the console:

let a = 10;
let b = 3;

if (a % b === 0) {
	console.log('is divisible');
} else {
	console.log('is divided with a remainder ' + a % b);
}

In the code above, it turns out that the remainder is calculated in two places, and this is not optimal. Let's fix the problem:

let a = 10;
let b = 3;
let rest = a % b;

if (rest === 0) {
	console.log('is divisible');
} else {
	console.log('is divided with a remainder ' + rest);
}

As you know, even numbers are divided by 2 without a remainder, and odd numbers with a remainder. Let's say you have a number. Use the operator % and the construct if to check if this number is even or not.

Given a number. Check that it is divisible by 3.