Explain the benefits of CSS sprites?

Most importantly there is a performance benefit as CSS sprites reduce page load time by minimizing HTTP requests for different images. Usually there is also an accessibility benefit as the code degrades gracefully and shows text to screen readers, search engines, and browsers without CSS. I also think that CSS sprites are easier to manage [...]

Explain the difference between synchronous and asynchronous JS request?

Most importantly, synchronous request blocks JavaScript engine until the interaction with the server is complete. The user cannot click away, cancel request, or go to another tab during this time. It is bad for user experience and that is why we have AsynchronousJAX. (AJAX)

Explain briefly the difference between normal array and associative arrays?

This kind of a question could be rephrased as “explain the difference between a['one']=’dog’ and a[one]=’dog’” because the main difference between a normal array in JavaScript and associative arrays is that associative arrays use Strings instead of Integer numbers as index. But this is also kind of a trick question as JavaScript does not support [...]

What is the difference between undefined value and null value?

In JavaScript, undefined means that a value has been declared but has not yet been assigned a value, such as null, which can be assigned to a variable as a representation of no value. If a value is null, it was assigned programmatically, as JavaScript never sets a value to null on its own. Also, [...]

What is the main difference between window.onload and onDocumentReady?

Both functions are used to perform tasks when the page is loaded in the browser but they have important differences. Most importantly, “window.onload” will execute code when browser has loaded the DOM tree and all other resources like images, objects, etc, while onDocumentReady allows you to execute code when only the DOM tree has been [...]

Div Vs SPAN

DIV is used to select a block of text so that one can apply styles to it. SPAN is used to select inline text and let users to apply styles to it. The main difference between DIV and SPAN is SPAN does not do formatting by itself. Also the DIV tag is used as a [...]

What is the difference between the Web and the Internet?

From the definition in the Wikipedia: “The Internet is a global system of interconnected computer networks that interchange data by packet switching using the standardized Internet Protocol Suite (TCP/IP).” Thus, the Internet is defined by the TPC/IP standards. The Web, on the other hand, is defined in W3C’s Architecture of the World Wide Web, Volume [...]

What does W3C do?

W3C’s primary activity is to developing protocols and guidelines that ensure long-term growth for the Web. W3C’s standards define key parts of what makes the World Wide Web work. The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards. Led [...]

HTTP protocol?

HTTP stands for Hypertext Transfer Protocol and it is the foundation of data communication for the world wide web. HTTP functions as a request-response protocol in the client-server computing model. In HTTP, a web browser, for example, acts as a client, while an application running on a computer hosting a web site functions as a [...]

Framework, CMS

Software framework, a reusable set of libraries or classes for a software system (or subsystem). o Application framework, a software framework used to implement the standard structure of an application for a specific operating system. o Web application framework, a software framework for development of dynamic websites, web applications, and web services Most developers work in a [...]