Write a full class definition for a class named GasTank and
Write a full class definition for a class named GasTank, and containing the following members:
A data member named amount of type double .
A constructor that accepts no parameters . The constructor initializes the data member amount to 0.
A function named addGas that accepts a parameter of type double . The value of the amount instance variable is increased by the value of the parameter .
A function named useGas that accepts a parameter of type double . The value of the amount data member is decreased by the value of the parameter . However, if the value of amount is decreased below 0, amount is set to 0.
A function named isEmpty that accepts no parameters and returns a boolean value . isEmpty returns a boolean value : true if the value of amount is less than 0.1, and false otherwise.
A function named getGasLevel that accepts no parameters . getGasLevel returns the value of the amount data member.
Solution
public class GasTank {
    private double amount;
   public GasTank() {
        // TODO Auto-generated constructor stub
        this.amount = 0;
    }
   public void addGas(double value) {
        this.amount += value;
    }
   public void useGas(double value) {
        this.amount -= value;
        if (this.amount <= 0)
            this.amount = 0;
    }
   public boolean isEmpty() {
        if (this.amount < 0.1)
            return true;
        else
            return false;
    }
   public double getGasLevel() {
        return this.amount;
    }
 }

