IDE(Integrated Development Environments):
For beginners there are many IDE’s but I’d recommend dr. java IDE. It is very light weight and easier to learn.
For advanced users there are IDE’s such as Eclipse, NetBeans, Android Studio, Intellijidea.
Before installing the IDE make sure you have the latest JDK and JRE installed on your system. In windows system set path if it is not set automatically. JDK 7, 8, JRE 7, 8 can have co-existing installation without causing errors.
- Package Declaration - Import Statements - Class Declaration
- Line Comments. Ex: // - Block Comments. Ex: /* Block Comment */ - Documentation Comment: Ex: /** * Documentation */
- Attributes / Instance Variables / Properties - Methods / Functions
- A way of grouping or arranging files in folders.
- Executed before constructor - When multiple constructors need to initialize the same instructions
- Declare a data type
- Assign values to variable
- Access current class instance members
Access members of an object:
- objectname.attribute - objectname.method()
- Constructors with same name but different types parameter or different amount of parameters
- Public: Can access from everywhere - Private: Access only from same class - Protected: Access from same class, sub / derived /child class, same package - Default: Access from same class, same package
Primitive Wrapper Class:
- A class based on primitive data types
- Inherit state, behavior from parent class
- A way of hiding, restricting access to class components
- Ability of object to take many forms - Pass is-a test