Take int of day, month, year and convert to DD/MM/YYYY

Question

I am writing a method to take a DOB of 3 integers - day, month, year and return the formatted version DD/MM/YYYY.

I am currently using dateFormatter and simple date form

Answer 1

Why use formatter? just do this:

   public String DateOfBirth(int day, int month, int year) 
{
    String DOB = day + "/" + month + "/" + year;

    return DOB;
}

If it's for an assignment, the teacher probably wants you to not use formatter.

Also, as someone else mentioned: If you are trying to concatenate integers as a string you need some string in between. Otherwise you are summing the values of the integers.

Answer 2

tl;dr

LocalDate.of( 2017 , 1 , 23 )
         .format( DateTimeFormatter.ofPattern( "dd/MM/uuuu" ) )

23/01/2017

java.time

The modern way uses the java.time classes.

Avoid the old legacy date-time classes such as Date and Calendar as they are poorly designed, confusing, troublesome, and flawed.

LocalDate

LocalDate represents a date-only value without time-of-day and without time zone. Note that unlike the legacy classes, here the months have sane numbering 1-12 for January-December.

LocalDate ld = LocalDate.of( 2017 , 1 , 23 );

DateTimeFormatter

Generate a String representing that value by using a formatter object.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd/MM/uuuu" );

String output = ld.format( f );