JavaScript - check if specific year is leap

In this article, we would like to show you how to check if the specific year is leap in JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

const isLeap = (year) => {
  return year % 400 === 0 || (year % 4 === 0 && year % 100 !== 0);
}

console.log(isLeap(2000));  // true
console.log(isLeap(2001));  // false

Practical example

In this example, we check if the specific year is leap with the following conditions:

• check if the year is a multiple of 400,
• or if it's a multiple of 4 and not multiple of 100.

Then we return the appropriate value true or false depending on the result.

Runnable example:

// ONLINE-RUNNER:browser;

function isLeap(year) {
  if (year % 400 === 0 || (year % 4 === 0 && year % 100 !== 0)) {
    return true;
  }
  return false;
}

console.log(isLeap(2000));  // true
console.log(isLeap(2001));  // false
console.log(isLeap(2002));  // false
console.log(isLeap(2003));  // false
console.log(isLeap(2004));  // true

Output:

true
false
false
false
true