Web Technology Questions

- A web worker is a JavaScript which runs in the background. It exists in external files. 

 - It is independent of other scripts and does not affect the performance of the page. 

 - Web workers are usually used for CPU intensive tasks.

Web browser is a software application used to locate,retrieve and display content on the World Wide Web, including Web pages, images, videos and other files.

Examples : Microsoft Internet Expiorer , Mozilla Firefox , Google Chrome, Opers , Safari etc...

- The traffic can be measured using the size of the files that are transferred from one place to another (server-client). 

- It can also be measured by the size of the file that is being requested by the client from the server. 

- The number of visitors arriving on the website also involve in the measurement of the traffic using the web hosting platform. 

- The advertisements of the sites take more bandwidth to allow more number of users to be on the website. 

- More number of users provides higher traffic on the website thus it requires more bandwidth on the web hosting sites.

JavaScript:

- JavaScript is a scripting language developed by Netscape Communications.

- The Netscape Navigator interprets JavaScript embedded into Web pages.

- JavaScript is used for developing web applications.

- It is not dependent on Sun Microsystem's Java language.

JScript:

- Microsoft JScript is an open implementation of Netscape's JavaScript.

- JScript is a scripting language designed to create active online content. ActiveX controls, Java programs, etc can be linked and automated in the web pages using JScript.

Pseudo elements allow the use of the part of element and not the element itself. They are applied to block level element, which is used for the complete block for which the CSS is being written. This allow the subpart of an element to be styled like paragraphs and headings. For example:

selector:pseudo-element {property:value;}

p: first-line {text-transform: lowercase;}

It adds the style to the first line of the code in the paragraph.

JavaScripts uses a hierarchical structure that applies to the objects in a document. There are some objects that show the relationship of one object to another using the language.

Window object: This is the topmost object in the hierarchy. It represent the content area of browser window that consists of HTML documents. Each frame is also a window that has some actions inside it.

Document object: This object gets loaded in a window and consists of objects of different kind in the model. It consists of the content that will be written in the script.

Form object: Form objects are used for more interaction with the users. It represents the form elements inside <FORM>...</FORM> tag.

SQL Server is having a fantastic feature to retrieve data persisted in the form of XML format. The data in the XML format can be retrieved using FOR XML clause appending to the SELECT statement.

It offers 3 modes.

- “FOR XML AUTO": Returns XML elements that are nested, based on which tables are listed in the "from" part of the query, and which fields are listed in the "select" part.

- "FOR XML RAW": Returns XML elements with the "row" prefix (ex: ""). Each column in a table is represented as an attribute and null column values aren't included.

- "FOR XML EXPLICIT": Explicit mode is the most complex shaping method used in SQL Server 2000. It allows users to query a data source in such a way that the names and values of the returned XML are specified before the query batch is executed. 

- The infinite file error can be solved when the data will be read continuously from the file. 

- The error can be solved by using the keys that provide only the resources that are required. 

- The following program is as follows:

osw.write ("HTTP/1.0 200 OK\n\n"); 

while (c != -1) { 

sb.append((char)c); 

c = fr.read(); 

} 

osw.write (sb.toString()); 

- This converts the requested file in such a way that if the file exists it shows the messages as ok otherwise it shows an error.

- Limited file access is to be given to the file to remove the error from the infinite file type.