Question

Java HW

Define a class called Counter whose objects count things. An object of this class records a count that is a nonnegative integer. Include methods to set the counter to 0, to increase the count by 1, and to decrease the count by 1.

Be sure that no method allows the value of the counter to become negative. Include an accessor method that returns the current count value and a method that outputs the count to the screen. There should be no input method or other mutator methods. The only method that can set the counter is the one that sets it to zero. Also, include a toString method and an equals method. Write a program (or programs) to test all the methods in your class definition

Answer 1

public class Counter
{
    private int value;

    /**
     Sets the counter to zero
     */

    public void setZero()
    {
        value = 0;
    }

    /**
     Increment counter by one
     */

    public void increment()
    {
        value++;
    }

    /**
     Decrements value by one, but does not go below zero
     */

    public void decrement()
    {
        value--;
        if(value < 0) {
            value = 0;
        }
    }

    /**
     Returns the counter's value.
     */

    public int getValue()
    {
        return value;
    }

    /**
     Displays the counter's value.
     */

    public void printCounter()
    {
        System.out.println(value);
    }

    public static void main(String[] args)
    {
        Counter testCounter = new Counter();

        testCounter.setZero();
        System.out.println("After setZero() testCounter = " + testCounter.getValue());

        int i;
        for(i = 0; i < 10; i++)
        {
            testCounter.increment();
        }

        System.out.println("After 10 increments testCounter = " + testCounter.getValue());
        testCounter.printCounter();

        for(i = 0; i < 11; i++)
        {
            testCounter.decrement();
        }

        System.out.println("After 11 decrements testCounter = " + testCounter.getValue());
        testCounter.printCounter();
    }
}