Java Important questions - 3

1) Name the methods of Object class?

clone() - This method helps to create and return a copy of the object.

equals() - This method helps to compare.

finalize () - called by the garbage collector on an object.

getclass() - It helps to return the runtime class of an object.

hashcode() - Helps to return a hash code value for the object

toString() - helps to return a string representation of the object.

notify(), notifyAll() and wait() - It helps to synchronize the activities of independently running threads in a program.

2) What are constructors in java? What are the types of constructors?

          In java, the constructor is a block of code used to initialize an object. The constructor is a method which has the same name as class name. There are two types of constructors:

1. Default constructor :

          A constructor that has no parameters is known as default constructor. If we don't define a constructor in a class, the compiler creates a default constructor for the class. 

2. Parameterized constructor :

          A constructor that has known parameter is a parameterized constructor. If we want to initialize field of the class with your own values,then use a parameterized constructor.

3) What is meant by local variable and Instance variable?

          Local variables are defined in the method and scope of the variables that have existed inside the method itself.

          An Instance variable is defined inside the class and outside the method and scope of the variables exist throughout the class.

4) What is the difference between static and dynamic loading ?

          Static loading : Classes are loaded statically with operator 'new'.

          Dynamic loading : It is the technique for programmatically invoking the functions of a class loader at runtime. The syntax is Class.forName(Test className);

5) What is an Anonymous class?

          The class defined without a name is known as an anonymous class.