Java Questions

It is the ability of an object to behave differently on different situations for the same message.

A throw is used to throw an exception manually, where as throws is used in the case of checked exceptions, to tell the compiler that we haven't  handled the exception, so that the exception will be handled by the calling function.

String class objects are immutable objects and they represents strings( sequence of characters)

StringBuffer class objects are mutable objects representing strings and they are Thread safe

StringBuild class objects are also mutable objects representing strings and they are not Thread safe

Pass By Reference means the passing the address itself rather than passing the value. Passby Value means passing a copy of the value to be passed.

Top level class is also called outer class. It is not defined inside any class.

Ex:

class A {  //top level class

}

The JVM performs three main tasks:

• Loads code

• Verifies code

• Executes code

If we print any object by using println() or print() methods.

The println() or print() methods internally calls tostring() method and prints the return value of toString() method.

Anonymous class is class without name.

EX:

class A {

}

class Demo {

    A r = new A() {

        }; //anonymous class

}