Question

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 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.
class GasTank
{
private:
double amount;
public:
GasTank();
void addGas(double);
void useGas(double);
bool isEmpty();
double getGasLevel();
};
GasTank::GasTank(){amount = 0;}
void GasTank::addGas(double a){amount += a;}
void GasTank::useGas(double a){amount -= a; if (amount < 0) amount = 0; }
bool GasTank::isEmpty(){if(amount < .1) return true; else return false;}
double GasTank::getGasLevel() {return amount;}

Answer 1

Answer:

Explanation:

The following class code is written in Java and includes all of the required methods as requested in the question...

package sample;

class GasTank {

   private double amount = 0;

   private double capacity;

   public GasTank(double initialAmount) {

       this.capacity = initialAmount;

   }

   public void addGas(double addAmount) {

       this.amount += addAmount;

       if (amount > capacity) {

           amount = capacity;

       }

   }

   public void useGas(double subtractAmount) {

       this.amount -= subtractAmount;

       if (amount < 0) {

           amount = 0;

       }

   }

   public boolean isEmpty() {

       return (amount < 0.1);

   }

   public boolean isFull() {

       return (amount > capacity - 0.1);

   }

   public double getGasLevel() {

       return amount;

   }

   public double fillUp() {

       double difference = capacity - amount;

       amount = capacity;

       return difference;

   }

}