Question

package simple; import java.awt.Frame; public class Scrubby extends Frame { int y; public Scrubby() { f(15); } int f(int x) { return x+y; } } the cross-reference tool generates the following report: e:/test/ # java JavaXref simple Parsing... e:\test\simple\Scrubby.java Resolving types... resolving: simple.Scrubby Writing report... Cross Reference Report ====================== A Java Cross-Reference Tool A Java Cross-Reference Tool 3 sur 13 Package: simple ----------------------------------------- simple.Scrubby (Class) [Scrubby.java:5] Superclass: Frame [Scrubby.java:3] Imported classes/packages: Frame simple.Scrubby.~constructor~ (Method) [Scrubby.java:8] simple.Scrubby.y (Variable) [Scrubby.java:6] Type: int Referenced: File: e:\test\simple\Scrubby.java Line: 13 simple.Scrubby.f (Method) [Scrubby.java:12] Referenced: File: e:\test\simple\Scrubby.java Line: 9 Return type: int Parameters: simple.Scrubby.f.x (Variable) [Scrubby.java:12] Type: int Referenced: File: e:\test\simple\Scrubby.java Line: 13

Hi what exactly does this code do?

Answer 1

Hi. This code that you provided (Scrubby class) does not generate any kind of output and it definitely not contain anything that relevant. But if you need the code explanation, please read the fully commented code explaining what’s happening in each line of this code. To put things simply, Scrubby class is extended from Frame class in java.awt package and has one instance variable named y, and has two methods – one default constructor and a method named f that takes an integer parameter.

Let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. If not, PLEASE let me know before you rate, I’ll help you fix whatever issues. Thanks

//imports Frame class of Java awt graphics library

import java.awt.Frame;

//defining a class named Scrubby extended from Frame class

public class Scrubby extends Frame {

      // defining an integer instance variable named y

      int y;

      // a constructor that initializes the Scrubby object

      public Scrubby() {

            // calling the f function, passing 15 as value. The function returns an

            // integer value, but since we don't store the value anywhere, this line

            // of code has no effect actually. but if we stored the returned value

            // in a variable, it should have the value 15, because f() function

            // returns the sum of value passed as argument(15) and the value of y

            // (currently 0)

            f(15);

      }

      // a method that takes an integer variable, returns the sum of that variable

      // and the instance variable y.

      int f(int x) {

            return x + y;

      }

}