I'm new to programming and I'm currently starting with java. I was wondering how to access elements of an object that I created. I thought I knew how but it doesn't seem to work. I'm constructing an object inside an inner class from a method, not in the inner class. I was wondering if you could give me some hints why it is not working when I want to access the values of the object that was just created. I mean can access the values, but they should be different from 0. It's as if my constructor didn't pass back the values. I did put my program in debugging and the values that are passed to the constructor are 0 , 2, 2. Thank you.

public class puzzle{

       public class Build{

             int nb, piece, length;

             public Build(int nb, int piece, int length){
                   //In debug I see that the values are passed, but when I print in the method the values printed are all 0.
                   nb = nb;
                   piece = piece;
                   length = length;
}

}
   public void rectangle(String book){
   
         //line of code where I do manipulations

         Build box = new Build(beginning, tv, book.length());

        System.out.println(box.nb);  
        System.out.println(box.piece); //should print a value different then 0
        System.out.println(box.length); //should print a value different then 0


}

}

CodePudding user response：

nb = nb;

This doesn't do anything. It sets nb to itself.

You have 2 completely, utterly unrelated variables here. One is called int nb; and is a field of your Build class. The other is a method parameter, by total coincidence also named nb.

You want to set the field, with the parameter value.

You have two options.

1. Stop using the same name. The method param 'takes precedence' (in java parlance: Shadows the field).

2. Use this.nb which refers to the field: this.nb = nb;.

The second form is idiomatic java. Do that.