adding days in a year

[Irving Luna]

I need to create a method for a program that accepts the date and if valid will add all the days from 01/01/xx to the date in the that year, eg 10/1/1999 will display "day 274 in 1999". I have the following code below, but its not adding the correct values. Not sure what I am doing wrong.

	public static int dayNumber(int day, int month, int year){
      int daysInMonth = 0;
      int days = 0;
      boolean leapYear = isLeapYear(year);
		for(int i = 1; i <= month; i++){
			switch(month){
				case 1: daysInMonth += 31;
				case 2: if(leapYear)
                     daysInMonth += 29;
                    else
                     daysInMonth += 28;
				case 3: daysInMonth += 31;
				case 4: daysInMonth += 30;
				case 5: daysInMonth += 31;
				case 6: daysInMonth += 30;
				case 7: daysInMonth += 31;
				case 8: daysInMonth += 31;
				case 9: daysInMonth += 30;
				case 10: daysInMonth += 31;
				case 11: daysInMonth += 30;
				case 12: daysInMonth += 31;
				break;
            default:
            break;
         }
         while(month <= 12){
            days += daysInMonth + day;
            month++;
         }
		}
		return days;
	}

[Piet Souris]

hi Irving,

first of all: contrary to every BASIC I know of, you must use "break" for each "case" statement,
otherwise things go horribly wrong.

Second: suppose you have a date in January, i.e. month = 1;
do you think it is right to set 'daysInMonth" to 31 (in your switch routine)?

Third: see line 06. Do you think you are using the correct variable here?

Lastly, what is the idea behind the "while" loop in line 26?

I suggest you put some System.out.println(variable) at handy places to see how your variables develop.

Greetings,
Piet

Edit: I just notice that the while-loop in line 26 is part of the for-loop. I thought is was outside.
Nevermind, just use the println() advice and you'll see what is happening.

[Irving Luna]

I found an easier method to do this, i'll have to come and review case-switches, thanks for the println adv though, ill be sure to use this to find where the bugs are coming from in the future.

[Jesper de Jong]

java.util.Calendar can do this already for you, you don't need to program it yourself.

Calendar cal = ...;
System.out.println("Day of the year is: " + cal.get(Calendar.DAY_OF_YEAR));