GNS | Java Classes

Java Classes

Posted in Code by Tieson | geeksneversleep.com

Nov

2008

If you are familiar with creating classes in C/C++, I have some good news and some bad news...

Good news: The concept of classes is the same in every OOP language, so you're at least one step ahead of new programmers.

Bad news: The syntax you used in C/C++ is different enough that you're probably going to spend a lot of time cursing at the Java compiler...

Similarities

Java is loosely based on C++, and implements OOP is more or less the same way. You can implement your code logic (say, from pseudo-code or UML diagrams) without much trouble, even if it was developed with specific C++ libraries in mind, as an equivalent library is probably available in the JRE (Java Runtime Environment).

Differences

While Java takes quite a bit of its base syntax from C and C++, it IS a different language, with its own quirks and strengths. One of the things that confused me when I first started to learn Java was the keywords it uses for its class structure. For instance, instead of namespace,Java uses package. Instead of inherits, you get extends.

Take a gander at this sample I put together for you:

• SampleClass.java


class SampleClass

{

   public SampleClass( 
void ) // constructor

   {

   /* place code here that needs to execute

   when an instance of our class is created */

   }



   
// private internal variables and functions go here

   private int age;

   private char[] name = 
new char[50];



   /* public shared variables and external functions

   go here */

   public int GetAge( 
void )

   {

     return age;

   }



   public void SetAge( 
int value )

   {

     age = value;

   }

}