C Program to check leap year

Arushi Dwivedi | March 13, 2021 | C Programming Example | No Comments

In this C Programming example, we will implement the program to check leap year using control statements, functions and print the output on the screen.

Table of Contents

1. What is a Leap Year?

A Leap Year is a calendar year that contains an additional day in the shortest month i.e. February has 29 days.

Fun Fact: Earth takes approximately 365.2425 days to orbit the Sun which is a solar year. But we consider a calendar year to be 365 days. And to cover this error almost every fourth year we add a day in the year. That is a leap year.

We can check whether the year is a leap year or not using the following conditions

If the year is divisible by 100 and 400 then it is considered a leap year.
If the year is divisible by 4 but not by 100, then also the year is considered as the leap year.

Example: 2000, 2024, 2028, 2036..etc.
These are all Leap Years.

Example: 1800, 1900, 2100 ..etc.
These are all not Leap Years because they are divisible by 100 but not by 400.

Helpful topics to understand this program better are-

2. C Program to check Leap year

Let’s discuss the execution(kind of pseudocode) for the program to check leap year in C.

Initially, the program will prompt the user to enter a year.
The program will then call for checkForLeapYear() function.
In this function, the year entered by the user will then be passed and the divisibility for the year to be a leap year or not is verified.
A year is a leap year if any of the conditions year % 4 == 0 && year % 100 != 0 or year % 100 == 0 && year % 400 == 0 is true.
If the year entered is found to be a leap year then it is printed onto the console otherwise, It is not a leap a year is printed onto the console.

Let us now implement the above execution of the program to check leap year in C.

#include <stdio.h>

void checkForLeapYear(int year) {
  if (year % 4 == 0 && year % 100 != 0) {
    printf("%d is a Leap Year", year);
  } else if (year % 100 == 0 && year % 400 == 0) {
    printf("%d is a Leap Year", year);
  } else {
    printf("%d is not a Leap Year", year);
  }
}

int main() {
  int year;
  printf("Enter year: ");
  scanf("%d", &year);
  checkForLeapYear(year);
  return 0;
}

Output
Enter year: 2024
2024 is a Leap Year

Output 2
Enter year: 1900
2024 is not a Leap Year

3. Conclusion

In this C Programming example, we have discussed what is a leap year and why do we have a leap year and we have also implemented the program to check leap year.

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