Kotlin Program to Check Leap Year

# 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

``````fun main(args: Array<String>) {

val year = 1900
var leap = false

if (year % 4 == 0) {
if (year % 100 == 0) {
// year is divisible by 400, hence the year is a leap year
leap = year % 400 == 0
} else
leap = true
} else
leap = false

println(if (leap) "\$year is a leap year." else "\$year is not a leap year.")
}``````

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.

Here's the equivalent Java code: Java Program to Check Leap Year

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

``````fun main(args: Array<String>) {

val year = 2012
var leap = false

leap = when {
year % 4 == 0 -> {
when {
year % 100 == 0 -> year % 400 == 0
else -> true
}
}
else -> false
}

println(if (leap) "\$year is a leap year." else "\$year is not a leap year.")
}``````

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.