java program help

chris1012 · November 5th, 2007, 10:21 AM

hey guys i was wondering if you could help me basically at the minute am working on an excercise with java programming for my Foundation Degree Course in computing. i've been working with the basics of java ie defining variables and setting up the jdk kit i've got a list of excercises which i have been asked to complete. the excercises are based on converting values ie miles yards and so on (college computers suck the jdk kit isn't even installed propperly on them) but what i've created so far is the Main.java file and the actual file itself which is named variable i would just like a bit of info on how to define this in a java based program note i am using edit plus when created java applications because at the minute i am only working with the command prompt at this stage the code i have got is as follows

class Main
{
    public static void Main(String[] args)
    {
    Scale scale =new Scale();
}
}

class Scale
{
    public Scale();
    {
        double mile=3.5
        int yards=6160
        int feet=18480
        int inches 221760
        System.out.println(miles * yards * feet * inches);

    }
}
the second section of code indicates the variables which i have setup what i have been asked is to convert from inches to feet and yards and miles. am not expecting anyone to do my work for me i just feel i need to grasp a better understanding of how the code works and what sort of code is used to carry out the calculation :( please help anyone i beg of you am dieing here:(

by the way sorry about the bad spelling afterall i am student lol

in opposite world i love programming

benatkin · November 5th, 2007, 04:00 PM

First, you need to make sure you use the right syntax. The compiler won't understand it otherwise. In Java that means never leaving out an equals sign and putting a semicolon after every statement. This will get your code to compile.

Next, be sure to pick good names for things. Instead of "yards", if you have a scaling factor to convert from a mile to yards, call it something like mileInYards.

Finally, make sure you understand what has to do with programming and what has to do with your domain (in this case, math). You may find it easier just to write the basic arithmetic and then translate it to Java.

Code that doesn't compile but illustrates what you're trying to do is called "psuedocode".

Finally, if you have a bad attitude about learning, you will have a harder time making the grade. Try to enjoy it.

chris1012 · November 5th, 2007, 04:37 PM

thanks m8 am just finding it difficult what code to use ie how to configure the layout and multiply what i need to sort of thing this java melarky tends to eb confusing lol but i will percivier thanks for your help

in opposite world i love programming

ciderpunx · November 8th, 2007, 09:35 AM

It can help to think of objects or classes as nouns/things and methods as verbs/actions.

If the question is "create a class that can convert a distance in miles to a distance in yards", perhaps what you're really after is a class called distanceInMiles (which is the thing in this sentence). You want that distance in miles to be able to tell you how far it is in yards - that's an action. So, you can make a method called toYards() which spits out the distance in yards. You can later add methods to spit out the distance in feet, inches, centimeters or whatever whenever you need to.

So as a rough idea:

Code:

public class distanceInMiles {
  float distanceInMiles;

  public distanceInMiles(float dist) {
    distanceInMiles = dist;  // Now we know how far we are in miles
  }

  public float toMiles() {
    return distanceInMiles;
  }

  public float toYards() {
    return distanceInMiles * 1760f;
  }

  public static void main (String argv[]) {
    distanceInMiles m = new distanceInMiles(1);
    System.out.println(m.toYards() + " yards");
  }
}

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