How to Create Objects in Java?

As per java, a class is nothing but blueprint of an objects, We create an object from a class. 
We have different ways to create object for class in Java.

1) Using new Keyword : 
Creating Object with new keyword is the  common way  in java.  By using this way we can call any constructor we want to call (no argument or parameterized constructors).

public class ObjectWithNew

{

    String name = "New Key Word";

    public static void main(String[] args) 

    {

        // Here we are creating Object of 

        // ObjectWithNew using new keyword

        ObjectWithNew obj = new ObjectWithNew();

        System.out.println(obj.name);

    }

}

 

 

2) Using New Instance : Suppose if we know the name of the class & it has a public default constructor we can create an object by Class.forName.  Class.forName loads the Class in Java, it doesn’t create any Object. To Create an Object of the Class we have to use the new Instance Method of the Class.

public class ObjectWithNewInstance

{

    String name = "Object with New Instance";

    public static void main(String[] args)

    {

        try

        {

            Class cls = Class.forName("ObjectWithNewInstance");

            ObjectWithNewInstanceobj =

                    (ObjectWithNewInstance) cls.newInstance();

            System.out.println(obj.name);

        }

        catch (ClassNotFoundException e)

        {

            e.printStackTrace();

        }

        catch (InstantiationException e)

        {

            e.printStackTrace();

        }

        catch (IllegalAccessException e)

        {

            e.printStackTrace();

        }

    }

}

 

 3) Using clone() method:

On calling  clone() for any object, the JVM creates a new object and copies all content of the previous object into it. Creating an object by the clone method does not invoke any constructor.
To use clone() method for an object we need to implement Cloneable and define the clone() method in it.

public class ObjectWithClone implements Cloneable

{

    @Override

    protected Object clone() throws CloneNotSupportedException

    {

        return super.clone();

    }

    String name = "Object with Clone";

  

    public static void main(String[] args)

    {

        ObjectWithClone  obj1 = new ObjectWithClone();

        try

        {

            ObjectWithClone obj2 = (ObjectWithClone ) obj1.clone();

            System.out.println(obj2.name);

        }

        catch (CloneNotSupportedException e)

        {

            e.printStackTrace();

        }

    }

}

 


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