[Java] public, private, final and basic rules for naming.

　　1. Access: public, private, protected

• public: Any other class can access a public field or method. (Further, other classes can modify public fields unless the field is declared as final.)
• private: Only current class can access. 
• protected: Accessible within all classes in the same package and within subclasses in other packages.

 

　　2. Declaration: static, final

• static: methods can be called without declaring an object of the class first.
• final: Means that constant, can not be modified. 

　　3. Naming rules

• Good class name rules: Words are capitalized , e.g.
  ThisIsAClass 
• Good mehod name rules: Spell out things where possible

  Lower case, second work on is capitalized, e.g.
  thisIsAFunction()

• Good variables name rules: Spell out things where possible

  Lower case, second work on is capitalized, e.g.
  numberRuns

• If it is final : All caps with underscores, e.g.THIS_IS_A_CONSTANT
• If it is class members: Begin with underscores unless they are public, e.g.
  • private String _thisIsAnInternalVariable


 

 

System.out.printf("%2d : [",numberRuns);

Enter value for A : 4
Enter value for B : 13
4 : [####]
13 : [#############]