Question

in java

Write a class Battery that models a rechargeable battery. A battery has a constructor

public Battery(double capacity)

where capacity is a value measured in milliampere hours. A typical AA battery has a capacity of 2000 to 3000 mAh. The method

public void drain(double amount)

drains the capacity of the battery by the given amount. The method

public void charge()

charges the battery to its original capacity.

The method

public double getRemainingCapacity()

gets the remaining capacity of the battery.

Supply a Battery class that tests all methods. Make sure to print the remaining capacity.

If we create an instance of Battery class with 2000 mAh, call drain (500) and then call getRemainingCapacity(), it should print 1500mAh; now if we call charge() and then call getRemainingCapacity() it should print 2000mAh

Answer 1

class Battery {

    private double initialCapacity;
    private double remainingCapacity;

    public Battery(double capacity) {
        this.initialCapacity = capacity;
        remainingCapacity = capacity;
    }

    public void drain(double amount) {
        remainingCapacity -= amount;
        if (remainingCapacity < 0)
            remainingCapacity = 0;
    }

    public void charge() {
        remainingCapacity = initialCapacity;
    }

    public double getRemainingCapacity() {
        return remainingCapacity;
    }
}

class BatteryTest {

    public static void main(String[] args) {
        Battery battery = new Battery(2000);
        battery.drain(500);
        System.out.println("Remaining capacity is " + battery.getRemainingCapacity());
    }
}