Question

Please help me with this Java problem. Would greatly appreciate comments in the code as well:

Define a class called Counter whose internal "count" variable is a basic integer counter. This class track that count from its instantiation in the constructor (can be set to any positive integer, or 0). The count should never be allowed to be negative. Include methods that will set the counter to 0, increase the count by 1, and decrease the count by 1.

Include an accessor method that returns the current count value (getCount()). There should be no input / setter method or other mutator methods. The only method that can set the counter is the one that sets it to zero (and the constructor).

This class should also override the Object class toString() and equals() methods - refer to the Java APIs for more guidance on how to override this (Chapter 8 also describes this in a little detail, but the API may be more useful): https://docs.oracle.com/javase/10/docs/api/java/lang/Object.html

Finally, write a main method (in this class) to test all the methods in your class definition.

Answer 1

Thanks for the question.

Here is the completed code for this problem.  Let me know if you have any doubts or if you need anything to change.

Thank You !!


@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


public class Counter {

    private int count = 0;

    public Counter() {
        this.count = 0;
    }

    public void incrementCounter() {
        this.count++;
    }

    public void decrementCounter() {
        this.count--;
    }

    public void resetCounter() {
        this.count = 0;
    }

    public Counter(int count) {

        this.count = count >= 0 ? count : 0;
    }


    public int getCount() {
        return count;
    }

    @Override
    public String toString() {
        return "Count Value: " + count;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Counter counter = (Counter) o;
        return count == counter.count;
    }

    public static void main(String[] args) {

        Counter counterA = new Counter(13);
        Counter counterB = new Counter();
        Counter counterC = new Counter(3);

        System.out.println("counterA = " + counterA);
        System.out.println("counterB = " + counterB);
        System.out.println("counterC = " + counterC);

        System.out.println("A = B ? " + counterA.equals(counterB));
        System.out.println("A = C ? " + counterA.equals(counterC));

        for (int i = 1; i <= 10; i++) counterB.incrementCounter();
        for (int i = 1; i <= 3; i++) counterA.decrementCounter();
        System.out.println("counterA = " + counterA); 
        System.out.println("counterB = " + counterB);
        System.out.println("A = B ? " + counterA.equals(counterB));
        counterC.resetCounter();
        System.out.println("Reset counterC = " + counterC);
    }

}

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Counter.java 43 public static void main (String [] args) [ 44 45 Counter counterA = new Counter(13); 46 = new Counter () Counter counterB 47 Counter counterC new Counter (3); 48 49 + counterA); System. out.println ("counterA = 50 counterB); System. out.println ("counterB 51 System. out.println ("counterc counterC) 52 = 53 = B? " + counterA.equals (counterB)); System.out.println("A 54 System.out.println("A = C ? " + counterA.equals (counterC) ) ; 55 5 6 for (int i = 1; i <= 10; i++ ) counterB.incrementCounter (); 57 for (int i = 1; i <= 3; itt counterA.decrementCounter () 58 System. out.println("A = B? " + counterA.equals (counterB)); 59 counterC.resetCounter ); 60 counterC); System. out.println ("Reset counterc E1 1 62 decrementCounter Counter Run Counter x "-javaagent:C:\Program Files "C:\Program Files\Java\jdk-l1\bin\java.exe" counterA Count Value: 13 Count Value: 0 CounterB counterC = Count Value: 3 A B false A C false A= B ? true Reset counterC Count Value: 0 Process finished with exit code 0 2: Favorites : Structure 1: Project