Java Questions

We can use the following method call:

boolean createNewFile();

This method creates a new file on the HD. 

If a file is already existing with the name given in the constructor then this method does not creates file on HD.

If file is successfully created then this method returns true.

If file is already existing on the HD then this method returns false.

This method may throw IOException whenever IO error is generated while creating file on HD.

Autoboxing is the process of converting a primitive type data into its corresponding wrapper class object instance.

Example:

Integer number = new Integer (100); // number is now refers to the object 100

Unboxing is the process of converting a wrapper instance into a primitive type.

Example: 

Integer number = new Integer (100); 

int num = number;// without type casting number would be changed into int type

Wrapped classes are classes that allow primitive types to be accessed as objects.

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

Ex:

class A {  //top level class

}

To use an iterator to traverse through the contents of a collection, follow these steps:

- Obtain an iterator to the start of the collection by calling the collections iterator() method.

- Set up a loop that makes a call to hasNext(). Have the loop iterate as long as hasNext() returns true.

- Within the loop, obtain each element by calling next().

Dynamic binding is orthogonal to dynamic linking. Binding refers to the linking of a procedure call to the code to be executed in response to the call. Dynamic binding It is associated with polymorphism and inheritance, it(also known as late binding) means that the code associated with a given procedure call is not known until the time of the call at run-time.

By using overloading we can add new functionality to the sub class.

Interface data is static data why bcoz interface supports multiple inheritance.

if inteface data is non-static then there is chance for replication of the data (bcoz of replication of data ambiguity problem occurs )