safari safari - 1 month ago 13
Android Question

Check if DAY_OF_WEEK is between Monday and Friday

I'm trying to create a method which is checking if "today" is between Monday and Friday. For this I get with this line

'int day = Calendar.DAY_OF_WEEK;'
the actual day. After that I fill a ArrayList with the days (Monday, Tuesday, Wendsday, Thursday and Friday). Now when I check if the actual day is in my ArrayList, i set
boolean DAY = true
else i set
boolean DAY = false
. I tryed the Method today and yesterday, but it allways sets the boolean to false.

What do I need to change that my code works? You'll find the code down here.

Code

int day = Calendar.DAY_OF_WEEK;
ArrayList<Integer> daylist = new ArrayList<Integer>();
daylist.add(Calendar.MONDAY);
daylist.add(Calendar.TUESDAY);
daylist.add(Calendar.WEDNESDAY);
daylist.add(Calendar.THURSDAY);
daylist.add(Calendar.FRIDAY);

if (daylist.contains(day)){
DAY = true;
}else{
DAY = false;
}

Answer

Wow, that's like trying to kill a mosquito with a thermo-nuclear warhead :-)

Java guarantees (in 1.5) (unchanged up to 1.8 at least) that the values of SUNDAY through SATURDAY are contiguous (1 through 7) so it's a simple matter of checking a range.

However, DAY_OF_WEEK is not the day of the week, it's a field number (with the value 7) to be passed to the getter to retrieve the day of the week. The only time Calendar.DAY_OF_WEEK itself will match an actual day will be on Saturdays.

You can use code such as:

Calendar myDate = Calendar.getInstance(); // set this up however you need it.
int dow = myDate.get (Calendar.DAY_OF_WEEK);
boolean isWeekday = ((dow >= Calendar.MONDAY) && (dow <= Calendar.FRIDAY));

Following this, isWeekday will be true if and only if the day from myDate was Monday through Friday inclusive.