# What is the purpose modulo operator in JavaScript

The modulo operator (% symbol) in JavaScript is used to find the remainder of dividing one number by another. It is commonly used for cyclic operations, like wrapping values around a range or checking if a number is even or odd.

For example, if you divide 7 by 3, you get a quotient of 2 and a remainder of 1. In JavaScript, you could express this using the modulo operator as follows:

``````7 % 3 // returns 1
``````

The modulo operator is often used in programming to perform cyclic operations, such as wrapping values around a range of possible values. For example, if you want to increment a variable from 0 to 9 and then wrap it back to 0, you could use the modulo operator as follows:

``````let i = 0;
i = (i + 1) % 10; // i is now 1
i = (i + 1) % 10; // i is now 2
...
i = (i + 1) % 10; // i is now 0 (wraps around to the beginning of the range)
``````

It also allows you to insert values into a string at specific placeholders or format specifiers.

``````let name = 'Alice';
let age = 25;
let message = 'Hello, my name is %s and I am %d years old.';
console.log(message % (name, age));
``````

The `template literals` (introduced in ES6) are the preferred method for string formatting. Here’s an example of the same string formatting using template literals:

``````let name = 'Alice';
let age = 25;
let message = `Hello, my name is \${name} and I am \${age} years old.`;
console.log(message);
``````

## JavaScript modulo operator example

Simple example code of purpose modulo operator in JavaScript

``````// Find the remainder of dividing two numbers
let a = 7;
let b = 3;
let remainder = a % b;
console.log(remainder);

// wrap a value around a range
let value = 8;
let range = 5;
value = value % range;
console.log(value);

// check if a number is even or odd
let number = 7;
if (number % 2 === 0) {
console.log('The number is even');
} else {
console.log('The number is odd');
}

``````

Output:

In the first example, we use the modulo operator to find the remainder of dividing `a` by `b`. In the second example, we use the modulo operator to wrap `value` around a range of `range`. In the third example, we use the modulo operator to check if `number` is even or odd.

Comment if you have any doubts or suggestions on this JS operator topic.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

## Discover more from Tutorial

Subscribe now to keep reading and get access to the full archive.