Problem with executing simple code

[Laurent Jones]

Hi there,

I'm just going through the head first java book. The weird thing is it seems like i understand what i've learnt in java so far theoretically, but when I go to write the code myself, It's all over the place.

I wrote this up:

 public class TestStuff
{
      void go()
        {
            TestStuff t = new TestStuff();
            t.takeTwo(1,2);
        }
        
        void takeTwo(int x, int y)
        {
            int z = x + y;
           System.out.println("Total is " + z);
        }
}

Now i know I haven't got a main method, but where do I put the main method and what do I put in the main method to print out ("Total is " + z.)

I've tried putting the main method underneath public class TestStuff but didn't work, I put it underneath all of the code but didn't work, I tried calling the go method by writing new go(); and called the takeTwo(); but no luck.

Please help so I can get the basics right from the start

[Jeanne Boyarsky]

You are really close. If you changed your go method signature to public static void main(String[] args), you'd be good to go. The go() method is creating an object and calling the method which is exactly what you want your driver method to do.

[Laurent Jones]

Ohh I see!! Thank's a lot for your help!

[Benjamin Thvedt]

I'm new to java myself, personally I would have tried to put the main in some different class, but I didn't know classes could have an object of themselves, within themselves, like that, if that makes sense. You know I would have the teststuff class with the method, and then I would hava a different class "TheProgram.java" or whatever that would have a teststuff object in it that I could use, if that makes sense.

Something like this:

class TheProgram {
     TestStuff t = new TestStuff(); // the object I want to test (already written)
     public static void main(String[] args) {
          t.takeTwo(1,2); // the method I want to test
     }
} 

I'm pretty new myself, but I think that would work. Then I would run TheProgram and see if that works. Just another way is all.

[Jeanne Boyarsky]

Benjamin,
That's close to working. You'd need to make the variable static or better yet, put it inside the main method. The reason is that it is currently an instance variable and a static method cannot access an instance variable.

[Benjamin Thvedt]

Whoops! My bad.