Question

Write a class named GasTank containing:

• An instance variable named amount of type double, initialized to 0.
• A method 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 method named useGas that accepts a parameter of type double. The value of the amount instance variable is decreased by the value of the parameter. However, if the value of amount is decreased below 0, amount is set to 0.
• A method named isEmpty that accepts no parameters. isEmpty returns a boolean value: true if the value of amountis less than 0.1, and false otherwise.
• A method named getGasLevel that accepts no parameters. getGasLevel returns the value of the amount instance variable.

Answer 1

//GasTank.java
public class GasTank {
  private double amount = 0;

  public void addGas(double amt){
    amount += amt;
  }

  public void useGas(double amt){
    amount -= amt;
  }

  public boolean isEmpty(){
    return amount<0.1;
  }
  
  public double getGasLevel(){
    return amount;
  }
}