Q: Getting Week for a given number from a String of the form `SunMonTueWedThuFriSat` Ok, I am stumped here. I really looked into this and cant seem to find specifically what I am trying to do. I am two weeks into Java in school and new to programming so please pardon any errors I may make. 
I am working on a string manipulation program and among other tasks in it I am to create a sting called names that holds SunMonTueWedThuFriSat, now I need to figure out how to grab and display in JOptionPane the 3 characters in that string that go with the numbers I am supposed to associate with them (0=Sun, 1=Mon, etc.) So if the user inputs 2 it should display Tue. I have a basic understanding on how to display those characters in a string, but for the life of me i cant seem to figure out how to associate those numbers with those characters. Every time I try to work something I keep getting errors and frustration. 
Thanks for all your help!!!

A: If the days of the week has to be in a single string, you can parse the string for each 3 character substring, and store then in an ArrayList.  Then, the provided number will match the index of the Day of the Week in the List.

A: Check HashMap.
For example:
HashMap<int, String> aWeekMap = new HashMap();
aWeekMap.put(0, "Mon");
aWeekMap.put(1, "Tue");

System.out.println(aWeekMap.get(0)); // prints Mon.

In memory you can visualize as following:


A: If you can use an array of string, it will be easier:
String[] names = {"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};

int input = 2;

System.out.println("The day is " + names[input]);


A: You should be able to just use substring, since all the abbreviations are three characters.
String s = "SunMonTueWedThuFriSat";

Prompt the user to enter a number (0-6):
String in = JOptionPane.showInputDialog("Please input a number (0-6)");

Now convert it to a number
int choice = Integer.parseInt(in);

And select the right portion of the string:
String day = s.substring(choice*3, choice*3+3);

Now just show this day in a JOptionPane:
JOptionPane.showMessageDialog(null, "Information", "You chose: " + day, 
    JOptionPane.INFORMATION_MESSAGE));


A: use the follwing code 
private ArrayList arr=new ArrayList();
arr.Add(0,names.subString(0,2);
arr.Add(0,names.subString(3,5);
arr.Add(0,names.subString(6,8);
arr.Add(0,names.subString(9,11);
arr.Add(0,names.subString(12,14);
arr.Add(0,names.subString(15,17);
arr.Add(0,names.subString(18,20);

and
JOptionPane.showInputDialog(null, "Please choose a name", "Example 1",
        JOptionPane.QUESTION_MESSAGE, null, arr);

