Re: Need basic help....

From:
RedGrittyBrick <RedGrittyBrick@SpamWeary.foo>
Newsgroups:
comp.lang.java.help
Date:
Wed, 31 Oct 2007 16:28:20 +0000
Message-ID:
<4728ad25$0$8420$db0fefd9@news.zen.co.uk>
TheBigPJ wrote:

Ive got this far...

class q4 {


It is conventional to start classnames with a capital letter. e.g. Q4.
This avoids confusing other people who are reading youir code. "q4"
looks like a variable name or method name.

     class Q4

     char a;

    public static void main(String[] args) {

I find it easier to read if you indent the contents of methods a further
  four spaces. This is a Java convention.

     q4 blah = new q4();
    blah.newa();
    blah.newa(); //must put command line here

I don't understand your comment.

 From your homework description you need to instantiate a *separate*
object and initialise it with a specific value.

         Q4 object2 = new Q4();
         object2.newa('b');

Normally you allow for initialisation in the constructor. you can have
several constructors with different "signatures" (same name, different
number or types of argument)

         Q4 object2 = new Q4('b');

     blah.returna();

You are throwing away the returned value.

         char retrievedChar = blah.returna();

There is a convention that "accessor" methods have names starting "get"
and that words within a variable name or method name are distinguished
by capitalizing the first letter of each word:

         char retrievedChar = blah.getA();

Maybe you should use the result in some way?

         System.out.println(retrievedChar);
or just
         System.out.println(blah.getA());

However your lecturer said your object should provide a method that does
this. I'd create a printA() method.

     }

    public void newa() {
    a = ' ';
    }

    public void newa(char a) {
    this.a = a;
    }

    public char returna() {

See earlier notes about accessor names.

     // Save to a file here

I'd have a separate saveToFile() method. Leave this until later.

         return a;
    }
}

But I don't think i am not on the right track :S


You're on the right track but could do some refactoring. I would proceed
in small steps and just try to satisfy the first one or two requirements
before adding more functionality.

You could be a bit more inventive with class and method names. If you've
already covered "inner classes" using one might help separate the
Question number from a meaningful name for the class that holds the
character.

class Q4 {

    public static void main (String[] args) {
        CharacterHolder firstCharacter = new CharacterHolder ();
        firstCharacter.printValueToScreen();

        CharacterHolder secondCharacter = new CharacterHolder ('b');
        secondCharacter.printValueToScreen();
        secondCharacter.printValueToFile("second character.txt");
    }

    class CharacterHolder {
        char value;
        public CharacterHolder() {
            value = ' ';
        }
        public CharacterHolder(char newCharacter) {
            value = newCharacter;
        }
        // etc etc
    }

}

I find that using long meaningful names helps me understand and
structure my code better. Using short names can quickly lead to confusion.

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