C# Examples

C# Program to Check Leap Year



A leap year is a calendar year in which an additional day is added to February month. In a leap year, the number of days in February month and the year are 29 and 366 respectively. A year that is not a leap year is called a common year. A year is said to be a leap year if:

  • it is divisible by 4.
  • it is divisible by 4 but not divisible by 100.
  • it is divisible by 4, 100 and 400.

Method 1: Using conditional statements

In the example below, conditional statements are used to identify a leap year.

using System;

class MyProgram {
  static void Main(string[] args) {
    int year = 2019;
    if (year % 400 == 0) {
       Console.Write(year + " is a leap year.");
    } else if (year % 100 == 0) {
       Console.Write(year + " is not a leap year.");
    } else if (year % 4 == 0) {
       Console.Write(year + " is a leap year.");
    } else {
       Console.Write(year + " is not a leap year.");
    }
  }
}

The above code will give the following output:

2019 is not a leap year.

Method 2: Using function

In the example below, a function called leapyear() is created which takes year as argument and prints whether the passed year is a leap year or not.

using System;

class MyProgram {
  static void leapyear(int year) {
    if (year % 400 == 0) {
       Console.Write(year + " is a leap year.");
    } else if (year % 100 == 0) {
       Console.Write(year + " is not a leap year.");
    } else if (year % 4 == 0) {
       Console.Write(year + " is a leap year.");
    } else {
       Console.Write(year + " is not a leap year.");
    }
  }

  static void Main(string[] args) {
    leapyear(2019); 
  }
}

The above code will give the following output:

2019 is not a leap year.