Check for Leap Year

Source Code

# Program to check if
# the input year is
# a leap year or not

year = as.integer(readline(prompt="Enter a year: "))
if((year %% 4) == 0) {
    if((year %% 100) == 0) {
        if((year %% 400) == 0) {
            print(paste(year,"is a leap year"))
        } else {
            print(paste(year,"is not a leap year"))
        }
    } else {
        print(paste(year,"is a leap year"))
    }
} else {
    print(paste(year,"is not a leap year"))
}

Output 1

Enter a year: 1900
[1] "1900 is not a leap year"

Output 2

Enter a year: 2000
[1] "2000 is a leap year"

In this program, we ask the user to input a year and check if it is a leap year or not. Leap years are those divisible by 4. Except those that are divisible by 100 but not by 400. Thus 1900 is not a leap year as it is divisible by 100. But 2000 is a leap year because it if divisible by 400 as well.