• A Simple Java Program
• Comments
• Data Types
• Variables
• Operators
• Strings
• Input and Output
• Control Flow
• Big Numbers
• Arrays

Sample：

    public class FirstSample  
        { 
            public static void main(String[] args)
               {
                   System.out.println("We will not use hello world!");
               }
        } 

First and foremost, Java is case sensitive, which means FirstSample is different with firstsample or Firstsample.

public: access modifier, controls the level of access other parts of a program have to this code.

class: think of a class as a container for the program logic that defines the behavior of application. Everything in Java programs must be inside a class.

(to be continued)