Reference Data Types

Reference Data Types

In this section we will discuss about Reference Data Types in Java 7.

Reference Data Types :

Non-primitive data types are also called reference data types. It is handled by reference. These refer to objects and arrays. it is created by defining constructor of a classes. You can use it to access the objects. Class objects and different type of array variables are described in reference data type.

You can define reference data type as a variable that can contain reference of dynamically created object. These are not predefined like primitive data type.
These are -

• array
• class
• interface

Array Type :
In general, array is a collection of similar type of data types.

Syntax :

DataType[] arrayVariable=new DataType[];

Example :

int[] n=new int[5];
String[] str=new String();

class Type :

Class is a template of variables and methods. Name of class refers as a type in java. By creating object of this class you can access class variables and methods.

Example :

Test.java

class Test{
int a=100;
public void display(){
System.out.println("Value of a:" +a);
}
}

MainClass.java

Class MainClass{
public static void main(String[] args){
Test test=new Test();
test.display();
}
}

Interface Type:
The another type of reference data type is Interface Type. It supports concept of multiple inheritance. You can use name of interface as type of reference.