gistfile1.java

import java.util.Scanner;

class NewCar {
	// instance variables
	double start, end, galls;

	// constructor
	NewCar(double start) {
		this.start = start;        
	}

	// methods
	void fillUp(double miles, double galls) {
	    if (end > 0)
	    	start = end;

	    end = miles;
	    this.galls = galls;
	}

	double mpg() {
		return (end-start)/galls;
	}

	public static void main (String[] args) {
		// get data, construct car
		Scanner keyboard = new Scanner(System.in);
		System.out.println("New car odometer reading:");
		double start = keyboard.nextDouble();
		NewCar car = new NewCar(start);
		  
		// 2 gas station visits
		for(int i=1; i<=2; i++) {
			System.out.println();
			System.out.println("Filling Station Visit");
			System.out.println("odometer reading:");
			double miles = keyboard.nextDouble();

			System.out.println("Gallons to fill tank:");
			double galls = keyboard.nextDouble();

			car.fillUp(miles ,galls);
			System.out.println("Miles per gallons: " + car.mpg());
		}
	}
}