Thread: Flaw in my code

What is wrong with my output?

Did you post it yet?

AutoTrip myTrip = new AutoTrip(distance, fuel);

Youre not supposed to train on your get-methods here. The assignment isnt to write a getMPG method that just returns a value. See how this piece of code doesnt have 3 inputs but 2? You get the distance and the fuel, the MPG has to be calculated inside the myTrip-object.

public AutoTrip(double distance, double fuel, double MPG){
  distance = miles;
  fuel = gallons;
  MPG = mileage;
}

Heres the error, youre using 3 input-variables here. Remove the double MPG and calculate it either in the constructor for AutoTrip, or in the getMPG method.

OK first of all see what happens when you change

distance = miles;

for

miles = distance;

Then as Charlie has said you'll want to calculate the MPG in the constructor and look here whats wrong with this

    AutoTrip myTrip = new AutoTrip(distance, fuel);

When your constructor is like this

public AutoTrip(double distance, double fuel, double MPG)

And I think Norm meant to post the output you actually got as in what came up on the screen although we did need that class too.

What's wrong with this?

private double distance;
private int fuel;
 
public AutoTrip(double miles, int gallons){
  distance = miles;
  fuel = gallons;
}
 
public double getDistance(){return distance;}
 
public int getFuel(){return fuel;}
 
public double getMPG(){return (distance/fuel);}

What do you mean by "wrong"? What is the code supposed to do?
Does it compile? Does it execute? If yes to both, then its not wrong on those counts.

Originally Posted by Norm

What do you mean by "wrong"? What is the code supposed to do?
Does it compile? Does it execute? If yes to both, then its not wrong on those counts.

Feedback:
The constructor you have written doesn't match the constructor call in the problem specification.

Output was not:
My car traveled 400.48 miles on 21.4 gallons of gasoline.
My mileage was 18.714018691588787.

Well you tell us what is actually happening now?

So what was the output? You have gallons as an int but you are passing it a double.

I still don't see your question. Try to be more specific than saying: "what's wrong".

Output was not:

Sorry I don't see where you posted your output.

Oh. I got it. Thanks!

I just spotted that by chance from now on don't tell us what the output wasn't tell us what it was. We can't tell much just from what you expect the programme to do can we?

public class Driver
{
  public static void main(String[] args)
  {
    double distance = 400.48;
    double fuel = 21.4;
    AutoTrip myTrip = new AutoTrip(distance, fuel);
    System.out.print("My car traveled " + distance + " miles ");
    System.out.println("on " + fuel + " gallons of gasoline.");
    double mileage = myTrip.getMPG(); // get miles per gallon
    System.out.println("My mileage was " + mileage + ".");
 }
 
}
 
 
 
 
public class AutoTrip 
{
private double distance;
private int fuel;
 
public AutoTrip(double miles, double gallonsl) {
  distance = miles;
  fuel = gallons;
}
 
public double getMPG(){ return (distance/fuel); }
}