How to add printing of number of days in a year also for leap years?

Question

I am having trouble adding it so that my program prints out the days in a certain year. What's messing me up is the leap years. Don't want to scrap it.

I am confused and was trying to put it together by myself and should have asked for help. wanted to know if there was a way to fix it or if i had to scrap it and start all over again. My problem so far is designating the days. since i'm not sure if i should just separate the days by the month over just have the total for each year and do that for the leap year as well.

if (month == 1) {
    month1 = "January"; 
    daysInMonth = 31;
} else if (month == 2 ) {
    month1 = "February";
    daysInMonth = 28;
} else if (month == 3) {
    month1 = "March";
    daysInMonth = 31;
} else if (month == 4) {
    month1 = "April";
    daysInMonth = 30;
} else if (month == 5) {
    month1 = "May";
    daysInMonth = 31;
} else if (month == 6) {
    month1 = "June";
    daysInMonth = 30;
} else if (month == 7) {
    month1 = "July";
    daysInMonth = 31;
} else if (month == 8) {
    month1 = "August";
    daysInMonth = 30;
} else if (month == 9 ) {
    month1 = "September";
    daysInMonth = 30;
} else if (month == 10) {
    month1 = "October";
    daysInMonth = 31;
} else if (month == 11) {
    month1 = "November";
    daysInMonth = 30;
} else if (month == 12) {
    month1 = "December";
    daysInMonth = 31;
} else if (month >= 13 ) {
    System.out.println("this date does not exist please try again");
}

if (month <= 12) {
    System.out.println("this is the year you put in " + year);
    System.out.println("this is the month you entered " + month1);
    System.out.println("this is how many days are in that year " + daysInMonth);
    }
}

Answer 1

You would get several advantages if you used java.time for this:

• it will be easier to check for invalid input
• you can easily find out if a year is a leap year or not
• you can easily print month names and even abbreviations depending on a locale, that means you can switch languages and standards

Here's a small example for a method:

public static void printInformationAbout(int month, int year) {
    // create an instance of month and year from the arguments
    Year y = Year.of(year);
    Month m = Month.of(month);
    
    // collect information about the year
    boolean isLeap = y.isLeap();
    int days = y.length();
    // and print that information
    if (isLeap) {
        System.out.println(year + " is a leap year and has " + days + " days");
    } else {
        System.out.println(year + " is a regular year and has " + days + " days");
    }
    
    // print month info (directly this time)
    System.out.println(String.format("%s (month no. %d) has %d days in %d",
                            m.getDisplayName(TextStyle.FULL, Locale.ENGLISH),
                            m.getValue(),   //  number of the month
                            m.length(isLeap), // length of month in days
                            year));
}

If you used this in a main, let's say like this:

public static void main(String[] args) {
    printInformationAbout(5, 2020);
}

You'd get the following output:

2020 is a leap year and has 366 days
May (month no. 5) has 31 days in 2020