Kotlin check if it is a leap year

Kotlin Comprehensive Examples

In this program, you will learn how to check if a given year is a leap year in Kotlin. It uses if else statements and when statements to check.

is a leap year4is divisible by400 is divisible by, only century years are leap years, but not those ending with 00. Only when it can be

Example1：Using if else statements to check the Kotlin program for Ko year

fun main(args: Array<String>) {
　　　　val year =　1900
　　　　var leap = false
　　　　if (year %　4　== 0) {
　　　　　　　　if (year %　100 == 0) {
　　　　　　　　　　　　//year can be divisible by400 is divisible by, therefore it 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 running the program, the output is:

1900 is not a leap year.

In the above program, the given year1900 is stored in the variable year.

• Because1900 is divisible by4is divisible by, and it is a century year (ending with 00), while leap years can be400 is divisible by. Because1900 is not divisible by400 is divisible by, so1900 is not a leap year.

• However, if we change year to2000, then it can be4is divisible by, and it is a century year, and it can also be400 is divisible by. Therefore,2000 is a leap year.

• Similarly, if we change the year to2012then the year can be4is divisible by, and it is not a century year, so2012is a leap year. We do not need to check2012The year can be divisible by400 is divisible by.

The equivalent Java code is as follows:Java program to check for leap year

Example2：Kotlin program uses when expression to check for leap year

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 running the program, the output is:

2012　It is a leap year.

In the above program, we used the when expression instead of if else statements.

The way the when expression works is as follows:

• If the year (year) can be 4 When divisible:

• If it can be4If divisible, check again whether year can be400 evenly divisible, then return true or false

• when another expression is entered, check if year can be100 evenly

• If it cannot be divided by100, then year is not a century year (ending with 00), then return true

• If year cannot be4If it is divisible, return false

According to the value of leap, it uses inline if else to print the output.

Kotlin Comprehensive Examples