Compressing Similar if Statements (Java)

Question

I am trying to select a certain array out of 16 depending on what value is passed into the constructor of a class. The value entered will be used in a series of if statements that will choose the array. Something like this

    package Model;

    import javax.swing.*;
    public class Die extends JButton{
         String letters[] = new String[6];
         public Die(int number){
               Controller con = new Controller();
               if(number==1){
                    for(int i = 0; i<5; i++}{
                        letters[i] = con.die1[i];
                    }
               }
               if(number==2){
                    for(int i = 0; i<5; i++}{
                        letters[i] = con.die2[i];
                    }
               }
               if(number==3){
                    for(int i = 0; i<5; i++}{
                        letters[i] = con.die3[i];
                    }
               }
         }
    }

(Keep in mind that I haven't checked this code, and I have not created all 16 if statements).
Basically I want to compress these if statements somehow. Any ideas?

Answer 1

Declare a Map<Integer, String[]> that associates the number to the String to each die array and you would have not any conditional statements.

Controller con = new Controller();
Map<Integer, String[]> map = new HashMap<>();   
map.put(1, con.die1);
map.put(2, con.die2);
map.put(3, con.die3);


if(number>=1 && number<=3){
    for(int i = 0; i<5; i++}{
        letters[i] = map.get(number)[i];
    }
}

And as suggested by Lino you could even move this mapping into the Controller class which makes more sense in terms of responsibility :

private Map<Integer, String[]> map = new HashMap<>();
public Controller(){
  map.put(1, die1);
  map.put(2, die2);
  map.put(3, die3);
}
public String getLetter(int number, int index){
    map.get(number)[index];
}

And the Die client could be now :

Controller con = new Controller();       
if(number>=1 && number<=3){
    for(int i = 0; i<5; i++}{
        letters[i] = con.getLetter(number, i);
    }
}