A leap year is a year that has 366 days. An additional day is added to the leap year to keep the calendar year synchronized with the astronomical year. You can check if a given year is a leap year or not using mathematics and programming.

In this article, you’ll learn how to check whether the given year is a leap year or not using C++, Python, JavaScript, and C.

## Problem Statement

You’re given a **year**. You need to check whether the given year is a leap year or not.

**Example 1**: Let year = 2021.

2021 is not a leap year.

Thus, the output is “2021 is not a leap year”.

**Example 2**: Let year = 1980.

1980 is a leap year.

Thus, the output is “1980 is a leap year”.

## Condition for a Year to Be a Leap Year

A year is a leap year if any or both of the following conditions are satisfied:

- The year is a multiple of 400.
- The year is a multiple of 4 and not a multiple of 100.

## C++ Program to Check Whether a Year Is a Leap Year or Not

Below is the C++ program to check whether a given year is a leap year or not:

`// C++ program to check if a given year is a leap year or not`

#include <iostream>

using namespace std;

bool isLeapYear(int y)

{

// If a year is a multiple of 4 and not a multiple of 100 or a multiple of 400,

// then the year is a leap year

// Multiple of 4 and (Not a multiple of 100 or Multiple of 400) => A Leap year

return (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0));

}

int main()

{

int year1 = 2021;

cout << "Year: " << year1 << endl;

if(isLeapYear(year1))

{

cout << year1 << " is a leap year" << endl;

}

else

{

cout << year1 << " is not a leap year" << endl;

}

int year2 = 2012;

cout << "Year: " << year2 << endl;

if(isLeapYear(year2))

{

cout << year2 << " is a leap year" << endl;

}

else

{

cout << year2 << " is not a leap year" << endl;

}

int year3 = 1980;

cout << "Year: " << year3 << endl;

if(isLeapYear(year3))

{

cout << year3 << " is a leap year" << endl;

}

else

{

cout << year3 << " is not a leap year" << endl;

}

int year4 = 1990;

cout << "Year: " << year4 << endl;

if(isLeapYear(year4))

{

cout << year4 << " is a leap year" << endl;

}

else

{

cout << year4 << " is not a leap year" << endl;

}

int year5 = 1600;

cout << "Year: " << year5 << endl;

if(isLeapYear(year5))

{

cout << year5 << " is a leap year" << endl;

}

else

{

cout << year5 << " is not a leap year" << endl;

}

return 0;

}

Output:

`Year: 2021`

2021 is not a leap year

Year: 2012

2012 is a leap year

Year: 1980

1980 is a leap year

Year: 1990

1990 is not a leap year

Year: 1600

1600 is a leap year

## Python Program to Check Whether a Year Is a Leap Year or Not

Below is the Python program to check whether a given year is a leap year or not:

`# Python program to check if a given year is a leap year or not`

def isLeapYear(y):

# If a year is a multiple of 4 and not a multiple of 100 or a multiple of 400,

# then the year is a leap year

# Multiple of 4 and (Not a multiple of 100 or Multiple of 400) => A Leap year

return (((y % 4 == 0) and (y % 100 != 0)) or (y % 400 == 0))

year1 = 2021

print("Year: ", year1)

if isLeapYear(year1):

print(year1, "is a leap year")

else:

print(year1, "is not a leap year")

year2 = 2012

print("Year: ", year2)

if isLeapYear(year2):

print(year2, "is a leap year")

else:

print(year2, "is not a leap year")

year3 = 1980

print("Year: ", year3)

if isLeapYear(year3):

print(year3, "is a leap year")

else:

print(year3, "is not a leap year")

year4 = 1990

print("Year: ", year4)

if isLeapYear(year4):

print(year4, "is a leap year")

else:

print(year4, "is not a leap year")

year5 = 1600

print("Year: ", year5)

if isLeapYear(year5):

print(year5, "is a leap year")

else:

print(year5, "is not a leap year")

## JavaScript Program to Check Whether a Year Is a Leap Year or Not

Below is the JavaScript program to check whether a given year is a leap year or not:

`// JavaScript program to check if a given year is a leap year or not`

function isLeapYear(y) {

// If a year is a multiple of 4 and not a multiple of 100 or a multiple of 400,

// then the year is a leap year

// Multiple of 4 and (Not a multiple of 100 or Multiple of 400) => A Leap year

return (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0));

}

var year1 = 2021;

document.write("Year: " + year1 + "<br>");

if(isLeapYear(year1)) {

document.write(year1 + " is a leap year" + "<br>");

} else {

document.write(year1 + " is not a leap year" + "<br>");

}

var year2 = 2012;

document.write("Year: " + year2 + "<br>");

if(isLeapYear(year2)) {

document.write(year2 + " is a leap year" + "<br>");

} else {

document.write(year2 + " is not a leap year" + "<br>");

}

var year3 = 1980;

document.write("Year: " + year3 + "<br>");

if(isLeapYear(year3)) {

document.write(year3 + " is a leap year" + "<br>");

} else {

document.write(year3 + " is not a leap year" + "<br>");

}

var year4 = 1990;

document.write("Year: " + year4 + "<br>");

if(isLeapYear(year4)) {

document.write(year4 + " is a leap year" + "<br>");

} else {

document.write(year4 + " is not a leap year" + "<br>");

}

var year5 = 1600;

document.write("Year: " + year5 + "<br>");

if(isLeapYear(year5)) {

document.write(year5 + " is a leap year" + "<br>");

} else {

document.write(year5 + " is not a leap year" + "<br>");

}

Output:

`Year: 2021`

2021 is not a leap year

Year: 2012

2012 is a leap year

Year: 1980

1980 is a leap year

Year: 1990

1990 is not a leap year

Year: 1600

1600 is a leap year

## C Program to Check Whether a Year Is a Leap Year or Not

Below is the C program to check whether a given year is a leap year or not:

`// C program to check if a given year is a leap year or not`

#include <stdio.h>

#include <stdbool.h>

bool isLeapYear(int y)

{

// If a year is a multiple of 4 and not a multiple of 100 or a multiple of 400,

// then the year is a leap year

// Multiple of 4 and (Not a multiple of 100 or Multiple of 400) => A Leap year

return (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0));

}

int main()

{

int year1 = 2021;

printf("Year: %d \n", year1);

if(isLeapYear(year1))

{

printf("%d is a leap year \n", year1);

}

else

{

printf("%d is not a leap year \n", year1);

}

int year2 = 2012;

printf("Year: %d \n", year2);

if(isLeapYear(year2))

{

printf("%d is a leap year \n", year2);

}

else

{

printf("%d is not a leap year \n", year2);

}

int year3 = 1980;

printf("Year: %d \n", year3);

if(isLeapYear(year3))

{

printf("%d is a leap year \n", year3);

}

else

{

printf("%d is not a leap year \n", year3);

}

int year4 = 1990;

printf("Year: %d \n", year4);

if(isLeapYear(year4))

{

printf("%d is a leap year \n", year4);

}

else

{

printf("%d is not a leap year \n", year4);

}

int year5 = 1600;

printf("Year: %d \n", year5);

if(isLeapYear(year5))

{

printf("%d is a leap year \n", year5);

}

else

{

printf("%d is not a leap year \n", year5);

}

return 0;

}

Output:

`Year: 2021`

2021 is not a leap year

Year: 2012

2012 is a leap year

Year: 1980

1980 is a leap year

Year: 1990

1990 is not a leap year

Year: 1600

1600 is a leap year

## Make Programming Easier Using Coding Apps

If you’re looking out for a fun way to learn to code, you can use some apps like Enki, Grasshopper, SoloLearn, Codeacademy Go, Hopscotch, Encode, etc. These apps provide great environments for learning to code in a fun and interactive way. They’ll help you stay on top of your game by coding wherever you are.