Technology Questions

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

Ex:

class A {  //top level class

}

Constructor is not a special method.

Constructor is block of code that is executed automatically whenever object of the class is created.

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.

The garbage collector assumes that all objects in the managed heap are garbage. It starts walking the roots and builds a graph of all objects reachable from the roots recursively. It stops when it attempts to add an object to the graph that it previously added. The graph contains the set of all objects that are reachable from the application's roots. Any object/s that is not in the graph is not accessible by the application, and is considered garbage. Collection only occurs when the heap is full. In such a case, each and every garbage object calls the Finalize method and reclaims the unused memory

First we need to create an instance of a JDBC driver or load JDBC drivers, then we need to register this driver with DriverManager class. Then we can open a connection. By using this connection , we can create a statement object and this object will help us to execute the query.

A Manifest file is a simple text file that tells the browser what to cache and what not to cache. 

There are three sections of a Manifest file:

i.) CACHE MANIFEST - Files listed here are cached after they are downloaded for the first time. 

ii.) NETWORK - Files listed here require a connection to the server, and are never cached

iii.) FALLBACK - Files listed here specify fallback pages if a page is inaccessible

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.

Session storage is same like local storage but the data is valid for a session. In simple words the data is deleted as soon as you close the browser.

To create a session storage you need to use “sessionStorage.variablename” . In the below code we have a created a variable called as “clickcount”.

If you refresh the browser the count increases. But if you close the browser and start again the “clickcount” variable starts from zero.

if(sessionStorage.clickcount)

{

sessionStorage.clickcount=Number(sessionStorage.clickcount)+1;

}

else

{

sessionStorage.clickcount = 0;

}