Web Technology Interview Questions and Answers

The main languages used for web-designing are

• HTML/HTML5: Base template
• CSS/CSS3: Styling
• JavaScript: Functionality
• PHP: Server side scripts
• Ruby on Rails

DHTML stands for Dynamic HTML. The first thing that we need to clear about DHTML is that it is neither a language like HTML, JavaScript etc. nor a web standard. It is just a combination of HTML, JavaScript and CSS. It just uses these languages features to build dynamic web pages. DHTML is a feature of Netscape Communicator 4.0, and Microsoft Internet Explorer 4.0 and 5.0 and is entirely a “client-side” technology.

Features of DHTML:

• Simplest feature is making the page dynamic.
• Can be used to create animations, games, applications, provide new ways of navigating through web sites.
• DHTML use low-bandwidth effect which enhance web page functionality.
• Dynamic building of web pages is simple as no plug-in is required.
• Facilitates the usage of events, methods and properties and code reuse.

There are four main components: XML, SOAP, UDDI, AND WSDL.

XML: eXtensible Markup Language is a uniform data representation and exchange mechanism.

SOAP: Simple Object Access Protocol, SOAP is a standard way of using XML vocabulary to enable programs on separate computers to interact across any network and describing messages between applications.

UDDI: Universal Description, Discovery, and Integration specification, UDDI is a mechanism to register and located WS based application.

WSDL: Web Services Description Language, this is a standard meta language to describe the services offered. Specifically, WSDL states what a request message much contain and what the response will look like in a clear notation. WSDL also defines where the service is available and what communications protocol is used to talk to that service.

IBM Web Services Browser, available on the IBM Alphaworks site, is a good and intuitive example of a real web service. The browser provides a series of web services demonstrations. Behind the scenes, it ties together SOAP, WSDL, and UDDI to provide a simple plug-and-play interface for finding and integrating web services. For example, you can find a stock-quote service, a traffic-report service, and a weather service. Each service is independent, and you can stack services like building blocks.

• Blinking, spinning or flashing images
• Black background with white, light or pale text
• Black backgrounds with dark text
• Busy tiled background images with any color text
• Everything Centered
• Too many images or Huge images
• List of links
• Too many headlines or Blinking text

Dreamweaver Templates enables webmasters to define “non-editable” and “editable” regions of a webpage, only in Dreamweaver template the “non-editable” regions can be edited. Any changes implemented to the Dreamweaver Template will update any HTML pages that use the template.

• The easiest difference is static HTML once rendered cannot be changed on the other hand dynamic HTML can be changed.
• Static web pages cannot have database access but dynamic pages can be connected to database.
• Using static HTML no interactions persist between user and server but dynamic HTML has capability to interact with the user.
• Static HTML does not require server side coding but dynamic HTML requires server side coding.
• No animation, games can be developed using the static HTML but on the other hand dynamic HTML can perform this task.

There are three steps to get a proxy object of a web service at the client side.

• Access UDDI node for a list of web services.
• Services thus responded by UDDI have URL pointing to DISCO or WSDL document.
• Parse DISCO and WSDL document and build a proxy object which can communicate with the web service.

In CSS, you would use CSS float when you want to make an element of your page be pushed to the right or left and make other elements wrap around it.

There are four operations available:

• One-way, where the operation can receive a message but will not return a response.
• Request-response, where the operation can receive a request and will return a response.
• Solicit-response, where the operation can send a request and will wait for a response.
• Notification, where the operation can send a message but will not wait for a response.

Some of the JQuery functions used for webpage designing include

• Simple slide panel
• Simple disappearing effect
• Chainable transition effect
• Accordion#1 and Accordion#2
• Animated hover effect
• Entire block clickable
• Collapsible panels
• Image replacement gallery
• Styling different link types

The older versions of calculators have several “cancel” button (C, CE). The CE button will only clear the last entry but does not interrupt with the current computation. For instance, if you enter 2+1 and then press CE, it would show 0, but the calculator expects a second operand for the addition. (2+ is still there in memory). So to ensure that nothing remains left in memory and to start a new calculation we often see people hitting clear button couple of times. It is not due to a flaw in the calculator’s design.

Version of Netscape navigator and Internet Explorer higher than 4.0 or 4.0 supports DHTML in easy way. But as compared to both browsers Internet Explorer 4.0+ supports the DHTML in the best way.

DHTML includes JavaScript to make the page dynamic and regardless of which scripts is written for and the scripts are designed in such a way that it can be compatible with as many numbers of browsers as possible. The most important thing that must be kept in the mind is that we must test the code before running it over the server or making it live. Also we certainly cannot guarantee that all users will use the browser that will support the scripts.

The answer is simply, XML. XML lies at the core of Web services, and provides a common language for describing Remote Procedure Calls, Web services, and Web service directories. Prior to XML, one could share data among different applications, but XML makes this so much easier to do. In the same vein, one can share services and code without Web services, but XML makes it easier to do these as well. By standardizing with XML, different applications can more easily talk to one another, and this makes software a whole lot more interesting. Try this course on getting started with XML to master this separate language.

Responsive design is an approach to building sites to provide an optimal viewing and interaction experience. It focuses on easy navigation of site with a minimum of scrolling, panning and resizing across all devices.

Bootstrap is the most popular CSS, HTML and JS framework used for developing responsive web design

In order to align picture so that one may be higher or lower than the other, use the align statement in your IMG SRC tag.

< IMG SRC = “http://www.xyz.com/chguy.gif” align=top > Also, you can use align=top or you can do align=middle/bottom

The operations between different software applications, which are running on a variety of platforms and frame-working, are supported by web services. This web services architecture provides the concepts, modelling, and understanding web services and relationships among the components. The WSA specifies the minimal characteristics that are very common for all web services and a number of characteristics to the needed web services. WSA is called interoperability architecture that means the global elements of a global web service network are identified by this architecture in order to perform the interoperability between the web services.

They are both style properties

Visibility: hidden: This property hides the element, but it still takes up space in the layout

Display: none: It eliminates the element completely from the document. It does not take up any space, even though the HTML for it is still in the source code.

It is preferable to store the image in GIF format if image consists of certain words because JPG has file compression features which may render the fonts unreadable.

Speaking in true sense there is nothing dynamic in DHTML but enclosing technologies such as CSS, JavaScript, DOM and the static markup language it becomes dynamic.

JavaScript: Whether we call it JavaScript, Jscript, or ECMAScript, it is the most common language used today for client-side scripting. The main reason for this JavaScript comes with virtually every browser. For example, an unload event could execute a JavaScript function to query the browser’s cookies collection to determine whether the user is a first-time visitor to the page.

CSS/CSS3: It stands for Cascading Style Sheet. This is used for the presentation part of the web page. In simple words it holds the designing of the page. The look & feel of the page completely depends on CSS. In DHTML CSS rules can be modified at both the document and the element level using JavaScript with event handlers, they can add a significant amount of dynamism with very little code.

DOM: It stands for Dynamic Object Model and it is the weakest link in DHTML as many of the browser does not support the DOM functionality. It defines the object and its properties. It is a standard way of accessing and manipulating the static content. The Document Object Model is a platform and language-neutral interface that allows program and scripts to dynamically access the content and update it.

• The first and foremost difference is HTML is mark-up language but DHTML is not a language.
• DHTML stands with combination of HTML, CSS, JavaScript and DOM but HTML alone is an enough although static.
• HTML cannot have nay server side code but DHTML may contain server side code also.
• In HTML there is no need for database connectivity but DHTML may require connecting to database as it interacts with user.

During beginning of mouse technology, it was found that given the low resolution of the screens in those days, drawing a straight line and a line at a 45-degree angle was easier to do and more recognizable than the straight cursor. Also, the tilted arrow can help the click position easier to calculate because the origin of the cursors bitmap was in the upper left. This saved the mouse tracking subroutine a calculation on every click.