Umm... I guess it's good that you put some effort to this, but this tutorial contains
bad information... Well the one you haven't copied from the Wiki.
Quote:(07-13-2011, 06:00 PM)1337 Wrote: [To see links please register here]
1.Java SE:
We need a Java Platform first, so we will download it from java.sun.com
The latest update is 6u26. Choose your Operating System and also make sure you download the correct xx-bit architecture. Ex: x86 or x64.
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Well what you need specifically for development is called Java Development Kit (JDK). Java Platform covers several products, including the JRE - Java Runtime Environment, which is needed to execute Java applications.
Quote:(07-13-2011, 06:00 PM)1337 Wrote: [To see links please register here]
2. Eclipse:
Now we need a Compiler to execute and run our Java programs.
There are two most popular compilers, Netbeans and Eclipse. I prefer Eclipse.
I would recommend you to use Eclipse IDE for Java EE Developers. Again make sure you choose the correct xx-bit architecture.
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Netbeans and Eclipse are NOT compilers.
Java compiler is part of the Java Development Kit and it's called javac, it's a command-line tool. Netbeans and Eclipse are IDEs - Integrated Development Environments, they provide set of tools for writing the code and management of the project and integrate themselves with the compiler and debugger and other tools from the JDK. They themselves are however not compilers, they call the javac to compile the source. However, Eclipse contains its own incremental Java compiler, that's part of JDT core.
Also, compiler doesn't run the program, Java Virtual Machine (JVM) does. Compiler generates something called bytecode from the source, which is "universal" machine code, which is then exected by the JVM.
Quote:(07-13-2011, 06:00 PM)1337 Wrote: [To see links please register here]
First Program(Hello World):
Strangely enough all programming languages starts with a Hello World program. So lets go ahead and type this.
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Okay... this is very embarrassing.
People please TEST the code you write here, because I often find that people post code that does not work. It's especially embarrassing if it's something as simple as Hello World for beginners. The problem is, that the class name
starts with a number and that is illegal according to syntax rules of Java. Please post code that definitely works next time. Name of a class in Java (and many other languages) can start with a letter or underscore, not a number or special symbols.
Also the public modifier is kind of unnecessary in this case - it works with packages, where it means that the class is available also to other packages, not just to its own package.
Quote:(07-13-2011, 06:00 PM)1337 Wrote: [To see links please register here]
We mostly use public class for obvious reasons. You can use any name it doesnt matter.
And what are these obvious reasons? Java is OOP based language and one of the main principles of OOP is encapsulation - hiding parts of code from the other code, so it cannot modify it incorrectly and cause problems. Exposing everything publicly undermines this concept and is a bad programming habit.
Also names do matter: name of the class can start only with a letter or an underscore and can contain letters, numbers and underscores. Anything else is illegal. Also in case of public specifier, name of the class must be the same as name of the file it is in.
Quote:(07-13-2011, 06:00 PM)1337 Wrote: [To see links please register here]
You can again you anything instead of args, it doesnt matter.
Again, not anything. It must comply with the rule: start with underscore or a letter and contain letters, numbers and underscores. Also it's not a very good idea to change this name, because it follows certain convention and these make the code more readable.
I appreciate some effort put into this, but perhaps next time you should devote more effort to this to test the code you post and research some more information if it complies with the standard Java language and if it's technically correct.
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