How to check if a year is leap year in JavaScript

In this Article we will go through how to check if a year is leap year only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const isLeapYear = year => (((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0));

// Get the number of days in February
const isLeapYear = year => new Date(year, 1, 29).getDate() === 29;