Why doesn't 'final String[][] ....' make it final?????

[Mo Bustany]

I declared a 2-dim array of strings as final. However, I'm able to modify the contents of the array.
1. Why??
2. How can I make the contents final?
Thank you

public class Cat  {
    public Cat() {
    }
    public void setProperties(final String[][] props)
    {
        props[1][1] = "Male";
    }
    public void printProperties(String [][] props)
    {
        for (int i=0; i < props.length; i++)
        {
            for (int j=0; j < props[i].length; j++)
                System.out.print(props[i][j] + " ");
            System.out.println();
        }
    }
    public static void main(String[] args) {
        Cat cat1 = new Cat();
        final String[][] props = { {"Color","Brown"}, {"Gender","Female"}, {"Mood","Pleasant"}, 
            {"Pregnant","No"} };
        cat1.setProperties(props);
        cat1.printProperties(props);
    }
}

[ Jess adjusted the line breaks so the page won't scroll horizontally ]
[ February 06, 2003: Message edited by: Jessica Sant ]

[Garrett Smith]

The fields of the array are not final, though the array isself is.
In a real-life situation, you'd make a cat object w/final fields.

class Cat{
    
    final static int MALE = 1, FEMALE = 0;
    int _age;
    final int _sex;
    final String _color;
    final String _name;
    boolean _neutered = false;
    
    public Cat(int age, int sex, boolean neutered, String color, String name){
    
        _age = age;
        _sex = sex;
        _neutered = neutered;
        _color = color;
        _name = name;
    }
    public static void main(String[] args) {
        
        // Init Geraldo the purple cat.
        System.out.println(new Cat(2, MALE, true, "purple", "Geraldo"));
        
        
    }
    public String toString(){
        char plural = (_age == 1 ? '\u0000' : 's');
        
        return ("Cat name: " + _name + ", " 
            + "age : " + _age +" year" + plural +" old, "
            + "sex: "+ (_sex == 1 ? "male " : "female, ")
            + " " 
            + "color: "+ _color );
    }
    
    
    
    public void setSex(int sex){
    // Compiler error: can't set sex.
        _sex = sex;
    
    }
}

[Jessica Sant]

the way Garrett wrote your class is a much more object oriented way of doing things. To make it even MORE so -- and to get some encapsulation goin' you'd mark all the Attributes of the cat glass private and create getters/setters for those attributes.
As for the reason why you're able to change the contents of your final string array... read on.
An array is really an object. Even an array of primitives is an object. So, just like when you mark any old object as final, that means that you can't change what object that variable refers to -- (that's what final does to reference variables) however you can change the state of the object it refers to.
So... check out this code snippet:

public class intArrays
{
   public static void main( String[] args )
   {
      final int[] one = {1, 2, 3, 4};
      final int[] two = {5, 6, 7, 8};
      int three[] = {1, 3, 5, 7};
      one[2] = 99;  //no problem changing the contents of the array
      two = three; //not ok! can't change the object it refers to!
   }
}

does that help?
[ February 06, 2003: Message edited by: Jessica Sant ]