# Modulo Operator(%) in JavaScript

This tutorial teaches how to use the modulo operator `%` in JavaScript.

## Remainder Operator `%` in JavaScript

It gives the remainder left over when one number `(dividend)` is divided by another number `(divisor)`. This operator is not the same as the `modulo` operator in other languages because it serves a different purpose. Their results are the same only for a positive dividend, but if we have a negative dividend `a` and a modulo operator is applied over it, then the results will be completely different. The result obtained by the expression `( (a % n) + n) % n` using the remainder operator in JavaScript is the same as the result obtained using the modulo operator in `a % n`.

## Example of Using Remainder Operator `%` in JavaScript

### Modulo With Positive Dividend

``````1 % -2 //  1
2 % 3  //  2
5.5 % 2 // 1.5
12 % 5  //  2
1 % 2  //  1
``````

### Remainder With Negative Dividend

``````-12 % 5 // -2
-1 % 2  // -1
-4 % 2  // -0
``````

### Remainder With NaN

``````NaN % 2 // NaN
``````

### Remainder With Infinity

``````Infinity % 2 // NaN
Infinity % 0 // NaN
Infinity % Infinity // NaN
``````

## Applications

### Is a Number Odd or Even?

We can check if an integer is even by checking if it is divisible by `2`. We can use the modulo operator’s return value. If it is `0`, it means the number is even.

``````function isEven(n) {
return n % 2 === 0;
}

isEven(6);// true
isEven(3);// false
``````

### the Fractional Part of a Number

We can do this simply by calculating `n % 1`.

``````function getFractionalPart(n) {
return n % 1;
}

getFractionalPart(2.5); // 0.5
``````

### Convert Minutes to Hours

When given a number `n` that represents the number of minutes and we want to convert it to hours and minutes, we can use the modulo operator.

``````const minutesToHoursAndMinutes = n => ({
hours: Math.floor(n / 60),
minutes: n % 60
});

minutesToHoursAndMinutes(123); // { hours: 2, minutes: 3 }
``````
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