Thread: How to use final operator.

I had thought final in Java was like const in C++ sorta, or that was what I had wondered upon learning about const in C++.

I had heard that you might not want a value to be changed and so passed a final object as a parameter and I tested it by changing the value and it let me.

What's more, I tried making the whole method final and then calling it and using the returned (anonymous) object to call a set method and it let me do it.

I thought "final" meant it can't be changed.

 
/**
 * Write a description of class Example here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Example
{
    // instance variables - replace the example below with your own
    private int x;
    private String words;
 
    /**
     * Constructor for objects of class Example
     */
    public Example(int x, String words)
    {
        setX(x);
        setWords(words);
    }
 
    public Example()
    {
 
    }
 
 
    public int getX()
    {
 
        return x;
    }
 
    public void setX(int x)
    {
        this.x = x;
    }
 
    public void setWords(String words)
    {
    this.words = words;
}
 
 
public String getWords()
{
return words;
}
 
// sets the values of this new Example object to the values of the parameter
public final Example copy(  final Example ex)
{
Example ex2 = new Example(ex.getX(), ex.getWords());
ex.setX(3);
return (ex2);
}
 
public static void main(String[] args)
{
Example ex = new Example(5,"bob");
Example ex2 = new Example(4, "mike");
ex = ex.copy(ex2);
ex.copy(ex2).setX(3);
System.out.println(ex.getX());
}
 
}

I had been trying to get it to see if there was a way in a clone method you could make it so the object you're cloning CAN'T be changed (by mistake) in the method.

Final is a keyword (not an 'operator'), which means different things in different contexts. Suggested reading:
final (Java) - Wikipedia, the free encyclopedia
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