Question

How to get the number of days in a given month of a given year with C

Answer 1

#include <stdio.h>
#include <stdbool.h>

bool isLeapYear(int year) {
    return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}

int daysInMonth(int year, int month) {
    int days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    
    if (month == 2 && isLeapYear(year)) {
        return 29;
    }
    
    return days[month - 1];
}

int main() {
    int year = 2024;
    int month = 2;

    printf("Days in month: %d\n", daysInMonth(year, month));
    printf("Days in month: %d\n", daysInMonth(2025, 1));
    printf("Days in month: %d\n", daysInMonth(2025, 2));
    printf("Days in month: %d\n", daysInMonth(2025, 4));

    return 0;
}


  
/*
run:
  
Days in month: 29
Days in month: 31
Days in month: 28
Days in month: 30
  
*/

 

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