Top Ten Errors Java Programmers Make
(How to spot them. How to fix/prevent them.)
Whether you program regularly in Java, and know it like the back of your hand, or whether you're new to the language or a casual programmer, you'll make mistakes. It's natural, it's human, and guess what? You'll more than likely make the same mistakes that others do, over and over again. Here's my top ten list of errors that we all seem to make at one time or another, how to spot them, and how to fix them.
10. Accessing non-static member variables from static methods (such as main)
Many programmers, particularly when first introduced to Java, have problems with accessing member variables from their main method. The method signature for main is marked static - meaning that we don't need to create an instance of the class to invoke the main method. For example, a Java Virtual Machine (JVM) could call the class MyApplication like this :-
MyApplication.main ( command_line_args );
This means, however, that there isn't an instance of MyApplication - it doesn't have any member variables to access! Take for example the following application, which will generate a compiler error message.
public class StaticDemo
{
