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Showing posts from September, 2010

Non Static Variables

Can be accessed only by creating an instance. It will be not be updated when a new instance of the object is created. public class NonStaticVariables {  public NonStaticVariables() {         instancecount++;     }     private   int instancecount;     public static void main(String args[]){         NonStaticVariables nsv=new NonStaticVariables();     System.out.println(nsv.instancecount);   NonStaticVariables nsv1=new NonStaticVariables();     System.out.println(nsv1.instancecount);     } }

Static Variables

Can Be Accessed directly in the main method. Static instance variable will be updated on creating a new instance of the  object. public class StaticVaribles {     public StaticVaribles() {         instancecount++;     }     private static  int instancecount;     public static void main(String args[]){     System.out.println(instancecount);     StaticVaribles sv=new StaticVaribles();     System.out.println(instancecount);         StaticVaribles sv1=new StaticVaribles();     System.out.println(instancecount);     } } /*output run: instancecount->0 instancecount->1 instancecount->2 */

innerclasses

I nner Classes in java: Inner classes are the nested classes. example of a inner class: class MyOuter{ class MyInner{ public void display(){ System.out.println("Inner class"); } } } Type- 1: aCCESS outer class variable from inner class class MyOuter{ private int i=10; class MyInner{ public void display(){ System.out.println("Accessing private member of the outer"+i); } } } Type-2: Create an Instance of Inner class in outer class: class MyOuter{ private int i=0; public void makeInner(){ /*Creating an instance of the inner class in the outer class*/ MyInner in= new MyInner(); /*call the inner class method*/ in.display(); } class MyInner{ public void display(){ system.out.println("Accessing private memeber of the outer"+i); } } } Type-3: Create an Instance of Inner claSS from outside outerclass class MyOuter{ private int i=15; public void makeInner(){ /*Creating an instance of the inner class in the outer