Java puzzle 17: Classes and objects

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The output of this code is 2y2. Add only one statement at line 20. As a result of your statement, the output of the program becomes 9×5.
What is that statement?

Java puzzle 17: Classes and objects

Level: Hard

public class MyClass
  int i = 2;
  String str;
  MyClass(String str)
    this.str = str;
  int myMethod(int i, String str)
    this.i = i += 2;
    this.str = str;
    return(i + 4);
  public static void main(String[] args)
    MyClass mc = new MyClass("x");
    MyClass mc2 = new MyClass("y");
    // add your statement here!
Author: Sar Maroof

Answer explanation

  1. The statement should reassign the variable i of the object mc.
  2. The same statement should reassign the value of the variable i and the object str of the object mc2.
  3. To do that we need to use the method myMethod. We can use the method to reassign the value of the variable i and the value of the object str of the object mc2.
  4. To reassign the value of the variable i of the object mc, we can simply reassign its value to the vlaue that the method myMethod returns as follows.
    mc.i = mc2.myMethod(3, “x”);

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Sar Maroof is graduated from HBO Amsterdam "higher professional education". He is a professional computer programming teacher, gives master classes and publishes technical articles. His experience with developing software started from 2001 and he has worked as a software developer for several big as well as small companies and later as a freelancer. He is the author of Java quizmaster and Build a Java application in 7 days.

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