Java wrong data format transformation

Question

I need a Java program that subtracts 5 years from the current year. Everything is working fine but after I run the program:

DateFormat dateFormat = new SimpleDateFormat("yyyy");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.YEAR,-5);
Date today = new Date();
String start = dateFormat.format(cal.getTime()).toString();
String end = dateFormat.format(today).toString();
double start_doub = Double.parseDouble(start);
double end_doub = Double.parseDouble(end);
System.out.println(start_doub);
System.out.println(end_doub);

The result is:

2012.0
2017.0

I don't know the reason why the program adds .0 after the year? How can I remove the last part?

Okay, this was my mistake, after you suggested to use integer instead of double I know the reason. Thank you! — adama, Oct 23 '17 at 13:22
If you are using Java 8 or 9 this is much easier using the `Year` class from the new date/time support. — greg-449, Oct 23 '17 at 13:25
Don’t use strings to extract a year. You already have a Calendar object. Use `cal.get(Calendar.YEAR)` to get the year. — VGR, Oct 23 '17 at 14:09
Use modern java.time classes instead. `Year.now( ZoneId.of( "Africa/Casablanca" ) ).minusYears( 5 )` — Basil Bourque, Oct 23 '17 at 14:34
Even if you insist on using the old and outdated classes — which I strongly discourage — you are overcomplicating things. You just need a `Calendar`. You can still do without `DateFormat`, `SimpleDateFormat` and `Date`. — Ole V.V., Oct 23 '17 at 17:51

score 0 · Accepted Answer · edited Oct 24 '17 at 02:13

Your code look like below

        DateFormat dateFormat = new SimpleDateFormat("yyyy");
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.YEAR,-5);
        Date today = new Date();
        String start = dateFormat.format(cal.getTime()).toString();
        String end = dateFormat.format(today).toString();
        int start_doub = Integer.parseInt(start);
        int end_doub = Integer.parseInt(end);
        System.out.println(start_doub);
        System.out.println(end_doub);

Java wrong data format transformation

1 Answers1