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J15 Java Inner ClassJ15 Java Inner Class

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What is an Inner Class?

Class declared within another class

Accessing the members of the inner class: Need to instatiate an object instance of an inner class

first Example:

innerObj.innerMember = 5;

//innerObj is an instance of the inner class//innerMember is a member of the inner class

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Accessing Members of Outer classwithin an Inner class

Methods of the inner class can directly accessmembers of the outer class Example:

1 class Out {2 int OutData;

3 class In {

4 void inMeth() {

5 OutData = 10;

6 }

7 }

8 }

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Java Program Structure: Inner Classes

1 class OuterClass {

2 int data = 5;

3 class InnerClass {

4 int data2 = 10;

5 void method() {

6 System.out.println(data);

7 System.out.println(data2);

8 }

9 }

10

11 //continued...

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Java Program Structure:

9 public static void main(String args[]) {

10 OuterClass oc = new OuterClass();

11 InnerClass ic = oc.new InnerClass();

12 System.out.println(oc.data);

13 System.out.println( ic.data2 );

14 ic.method();

15 }

16 }

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Java Inner ClassJava Inner Class