Write a class named ParkingMeter containing: An instance variable named timeLeft of type int , initialized to 0.

LANGUAGE: JAVA

CHALLENGE:

Write a class named ParkingMeter containing:
An instance variable named timeLeft of type int , initialized to 0.
A method named add that accepts an integer parameter . If the value of the parameter is equal to 25, the value of timeLeft is increased by 30; otherwise no increase is performed. add returns a boolean value : true if timeLeft was increased , false otherwise.
A method named tick that accepts no parameters and returns no value . tick decreases the value of timeLeft by 1, but only if the value of timeLeft is greater than 0.
A method named isExpired that accepts no parameters . isExpired returns a boolean value : true if the value of timeLeft is equal to 0; false otherwise.

SOLUTION:

public class ParkingMeter{
    private int timeLeft = 0;
    public boolean add (int x){
        if (x == 25)
        {
            timeLeft += 30;
            return true;
        }else{
            return false;
        }
    }

    public void tick(){
        if (timeLeft > 0)
        timeLeft–;
    }

    public boolean isExpired(){
        if (timeLeft == 0)
            return true;
        else
            return false;
    }
}