Java Inner Class :
What is an Inner Class?
Inner classes are also known as Nested class, is a class which is declared within another class.
Advantages of Inner Class:
- Inner class can access all the variables and methods of enclosing class including private members
- Useful for Interface Implementations used by enclosing class
- Fine control over interface implementation
Types of Inner Classes:
There are 4 types of Inner Classes,
- Static Nested Class
- Member Inner Class
- Method Local-Inner Class
- Anonymous Inner Class
Static Nested Class:
A class within another class is known as Static Nested Class
Member Inner Class:
Class created within a class but outside methods
Method Local-Inner Class:
Class created within a methods
Anonymous Inner Class:
Class created for implementing interface or extending class
Today, In this article we are going to see an example of Static Nested Class i.e. Class within a class
Syntax for creating object for Inner Class,
OuterClassName.InnerClassName ObjectofInnerClass = OuterClassObject.new InnerClassName();
This syntax may look like complex one, But once we are through with the code we can understand it easily.
public class InnerExample {
String text1="Outerclass Text";
private String outerText = "Accessing Outerclass Text";
private void printText()
{
System.out.println(text1);
}
//Inner Class
class Inner
{
public void printOuterText()
{
System.out.println("This is Inner Class Text");
System.out.println(outerText);
}
}
public static void main(String args[])
{
System.out.println("Outer Class Printing");
InnerExample innerexample = new InnerExample();
innerexample.printText();
System.out.println("Now Printing from Inner Class");
InnerExample.Inner inner = innerexample.new Inner(); //Inner Class Object Creation
inner.printOuterText();
}
}
In this code, We have declared private method and a private variable in the outerclass and that has been accessed by the Inner class.
OuterClassName.InnerClassName ObjectofInnerClass = OuterClassObject.new InnerClassName();
Creating object for Inner class,
InnerExample.Inner inner = innerexample(OuterclassObject).new Inner();
Output:
