In this example, you will learn to check whether the year entered by the user is a leap year or not.

To understand this example, you should have the knowledge of the following C programming topics:

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.

For example,

- 1999 is not a leap year
- 2000 is not a leap year
- 2004 is a leap year

```
#include <stdio.h>
int main() {
int year;
printf("Enter a year: ");
scanf("%d", &year);
if (year % 4 == 0) {
if (year % 100 == 0) {
// the year is a leap year if it is divisible by 400.
if (year % 400 == 0)
printf("%d is a leap year.", year);
else
printf("%d is not a leap year.", year);
} else
printf("%d is a leap year.", year);
} else
printf("%d is not a leap year.", year);
return 0;
}
```

**Output 1
**

Enter a year: 1900 1900 is not a leap year.

**Output 2
**

Enter a year: 2012 2012 is a leap year.