# Kotlin Program to Check Leap Year

In this program, you’ll learn to check if the given year is a leap year or not in Kotlin. This is checked using a if else statement and a when statement.

A leap year is exactly divisible by 4 except for century years (years ending with 00). The century year is a leap year only if it is perfectly divisible by 400.

## Example 1: Kotlin Program to Check a Leap Year using if else statement

1. fun main(args: Array<String>) {
2. val year = 1900
3. var leap = false
4. if (year % 4 == 0) {
5. if (year % 100 == 0) {
6. // year is divisible by 400, hence the year is a leap year
7. leap = year % 400 == 0
8. } else
9. leap = true
10. } else
11. leap = false
12. println(if (leap) "\$year is a leap year." else "\$year is not a leap year.")
13. }

When you run the program, the output will be:

1900 is not a leap year.

In the above program, given year 1900 is stored in the variable year.

• Since 1900 is divisble by 4 and is also a century year (ending with 00), it has be divisble by 400 for a leap year. Since it’s not divisible by 400, 1900 is not a leap year.
• But, if we change the year to 2000, it is divisible by 4, is a century year and is also divisible by 400. So, 2000 is a leap year.
• Likewise, If we change the year to 2012, it is divisible by 4 and is not a century year, so 2012 a leap year. We don’t need to check if 2012 is divisible by 400 or not.

## Example 2: Kotlin Program to Check Leap Year using when expression

1. fun main(args: Array<String>) {
2. val year = 2012
3. var leap = false
4. leap = when {
5. year % 4 == 0 -> {
6. when {
7. year % 100 == 0 -> year % 400 == 0
8. else -> true
9. }
10. }
11. else -> false
12. }
13. println(if (leap) "\$year is a leap year." else "\$year is not a leap year.")
14. }

When run the program, the output will be:

2012 is a leap year.

In the above program, instead of using an if else statement, we have used a when expression.

The when expression works as:

• When year is divisible by 4
• Another when expression is entered which checks if year is divisible by 100
• If yes, it again checks if year is divisble by 400 or not, and returns true or false
• If not divisble by 100, year is not a century year (ending with 00) and returns true
• If year is not divisible by 4, it returns false

Based on the value of leap, it prints the output using an inline if else.