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XML Interview Questions and Answers

What is XML?
The Extensible Markup Language (XML) is a general-purpose specification for creating custom markup languages.[1] It is classified as an extensible language, because it allows the user to define the mark-up elements. XML’s purpose is to aid information systems in sharing structured data.
What is the version information in XML?
The root element can be preceded by an optional XML declaration element stating what XML version is in use (normally 1.0); it might also contain character encoding and external dependencies information.
What is ROOT element in XML?
XML documents must contain one element that is the parent of all other elements. This element is called the root element.
If XML does not have closing tag will it work?
All XML Elements Must Have a Closing Tag otherwise it will produce error while accessing or parsing.
Is XML case sensitive?
yes it is. XML tags are case sensitive. With XML, the tag is different from the tag .
Opening and closing tags must be written with the same case.
What’s the difference between XML and HTML?
On the surface, XML and HTML look similar. Both use tags (such as or ) and attributes (such as align=”left” or type=”personal”) to add information to the content. In fact, a carefully prepared HTML document can double as an XML document. The difference is that HTML is a well-defined set of elements and attributes. For example, the following is a well-formed XML document, but because it only uses tags that are defined in HTML, it’s also an HTML document:
Message of the Day

There is no message of the day.

Try back tomorrow.

On the other hand, HTML has somewhat looser rules than XML, so some HTML documents are not well-formed XML documents.
Is XML meant to replace HTML?
xml is a portable document structure, which is not really for presentation. XSL or CSS may replace html, but really xml is meant to be a storage medium. It is like asking if databases will replace html.
The one aspect that makes this whole thing blurry is that html and now Xhtml is a subset of xml. It is just used to make documents render in browsers.
Can you explain why your project needed XML?
1. If we having huge datas to be transferred instead of sending all those datas as dataset you can opt xml.
2. XML is easy to parse and it enables a faster accessing of datas.
3. Case sensitiveness is an additional advantage in validating the authentication for the user.
4. XML can be passed irrespective of OS, port and protocol.
What is DTD (Document Type definition)?
A Document Type Definition (DTD) defines the legal building blocks of an XML document. It defines the document structure with a list of legal elements and attributes.
A DTD can be declared inline inside an XML document, or as an external reference
Although XML allows you to invent as many different elements and attributes as you need, these elements and attributes, as well as their contents and the documents that contain them, must all follow certain rules in order to be well-formed. If a document is not well-formed, any attempts to read it or render it will fail.
What is a valid XML?
XML that meets the constraints defined by its Document Type Declaration.
What is CDATA section in XML?
CDATA Sections are used to escape blocks of text containing characters which would otherwise be recognized as markup. All tags and entity references are ignored by an XML processor that treats them just like any character data. CDATA blocks have been provided as a convenience measure when you want to include large blocks of special characters as character data, but you do not want to have to use entity references all the time
What is XSL?
Extensible Style Language is a style sheet language aimed at activities such as rearranging the document that are not supported by CSS, though XSL and CSS share the same underlying concepts. XSL can be used to style XML documents u sing sets of rules and definitions of actions to be applied. XSL is a specification from the W3C.
What is Element and attributes in XML?
The basic building blocks of XML Schemas are elements and attributes. Data types define the valid content that elements and attributes contain. When you create XML Schemas, you define the individual elements and attributes and assign valid types to them. Elements describe data, whereas attributes are like properties of an element, in that they provide further definition about the element the way that properties describe characteristics of objects and classes.
An element describes the data that it contains. Elements can also contain other elements and attributes.
An attribute is a named simple-type definition that cannot contain other elements. Attributes can also be assigned an optional default value and they must appear at the bottom of complex-type definitions. Additionally, if multiple attributes are declared, they may occur in any order.
What are the standard ways of parsing XML document?
DOM and SAX parsers are the standard ways for parsing XML document.
In What scenarios will you use a DOM parser and SAX parser?
In some scenarios, SAX is easily the better choice for quick, less-intensive parsing and processing. In others, the DOM provides an easy-to-use, clean interface to data in a desirable format. You, the developer, must always analyze your application and its purpose to make the correct decision as to which method to use, or how to use both in concert.
What is XSLT?
Extensible Stylesheet Language Transformations. A programming language specialized for the transformation of XML documents.
Define XPATH?
A query language used to identify a set of nodes within a XML document. Originally defined to be used with XSLT, it is also used by XPointer and a simple subset is used in the xs:key, xs:keyref, and xs:unique W3C XML Schema elements. The XQuery specification will be a superset of the second version of XPath. This version will use type information provided by W3C XML Schema
What is an XMLReader Class?
Represents a reader that provides fast, non-cached, forward-only access to XML data.
XmlReader provides forward-only, read-only access to a stream of XML data. The XmlReader class conforms to the W3C Extensible Markup Language (XML) 1.0 and the Namespaces in XML recommendations.
What is XMLTextReader?
The XmlTextReader class requires fast access to XML data. It does not require reading the entire document into memory via the Document Object Model (DOM). The class is derived from the XmlReader class and implements all the methods defined in the XmlReader class. The following are the functions of the XmlTextReader class:
* It enforces rules of a well-formed XML document.
* It does not provide any data validation in a document.
* It checks the Document Type Definition (DTD) and DocumentType nodes for their well-formed structure, but does not validate these nodes by using the DTD.
How do we access attributes using “XmlReader”?
The XmlReader class provides various methods and properties for reading attributes. Attributes are most commonly found on elements. However, they are also allowed on XML declaration and document type nodes.
When positioned on an element node, the MoveToAttribute methods enable you to go through the attribute list of the element. After MoveToAttribute has been called, the node properties—such as Name, NamespaceURI, Prefix, and so on—reflect the properties of that attribute, and not the containing element it belongs to.
What does XmlValidatingReader class do?
Represents a reader that provides document type definition (DTD), XML-Data Reduced (XDR) schema, and XML Schema definition language (XSD) validation.
XmlValidatingReader implements the XmlReader class and provides support for data validation. Use the Schemas property to have the reader validate by using schema files that are cached in an XmlSchemaCollection. The ValidationType property specifies what type of validation the reader should perform. Setting the property to ValidationType.None creates a non-validating reader.

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HTML PHP XML

HTML, CSS & JavaScript Web Designer or Web Developer Interview Questions

HTML, CSS & JavaScript Web Designer or web Developer Interview Questions

HTML Web Standards Interview Question

 

What is a DTD? What DTD do you generally use? Why? Pros and cons.

A DTD is a Document Type Definition, also know as DOCTYPE. In a document served as text/html, the DOCTYPE informs the browswer how to interpret the content of the page. If the the doctype is not declared, the browser assumes you don’t know how to code, and goes into “quirks mode”. If you know what you are doing and include a correct XHTML DOCTYPE, your page will be rendered in “standards mode”.

Accessibility Interview Question

Importance in selecting font size for a web page?

Font sizes should be declared using relative measurement values, such as ems, via a style sheet, without the use of the term !important. There are issues with browser font size enlarging which can be rectified via CSS.

CSS Interview Question

a) What are the possible values for the display attribute that are supported by all browsers?

b) What is the default value for the display attribute for the image element? (what is the difference between inline and block level elements)
c)What does display: run-in do?
d) Difference between “visibility:hidden” and “display:none”? What are the pros and cons of using display:none?

Answer

main values: none, block, inline, list-item, run-in
all values: inline | block | list-item | run-in | compact | marker | table | inline-table | table-row-group | table-header-group | table-footer-group | table-row | table-column-group | table-column | table-cell | table-caption | none | inherit
default value: inline, block or list-item, depending on the element. The <img> is an inline element.
Run-in should make the run-in element be the first line of the next sibling block level element, if it is before a block level element that is not floated or absolutely positioned. If the next sibling is positioned or floated, then the run-in element will be a block level element instead of appearing in-line.
PPK’s Quirksmode explains it well. The w3schools lists table display values.
When visibility is set to hidden, the element being hidden still occupies its same place in the layout of the page. If the display is set to none, the element does not occupy any space on the page — as if it didn’t exist..

 

CSS Interview Question

Question

a) What are the five possible values for “position”?
b) What is the default/initial value for “position”?
c) How does the browser determine where to place positioned elements
d) What are the pros and cons of using absolute positioning?
e) if they are really advanced, ask about IE z-index issues with positioned elements.

Answer

a) Values for position: static, relative, absolute, fixed, inherit
b) Static
c) They are placed relative to the next parent element that has absolute or relative value declared
d) Absolutely positioned elements are removed from the document flow. The positioned element does not flow around the content of other elements, nor does their content flow around the positioned element. An absolutely positioned element may overlap other elements, or be overlapped by them.
e) IE treats a position like a z-index reset, so you have to declare position of static on the parent element containing the z-indexed elements to have them responsd to z-index correctly.

 

CSS Interview Question

Question:

Write a snippet of CSS that will display a paragraph in blue in older browsers, red in newer browsers, green in IE6 and black in IE7

Possible Answer:

#content p{color:blue}
html>body #content p {color:red}
* html #content p{color:green}
html>body #content p {*color:black;}

 

Basic Javascript Interview Question

Question:

What is the correct way to include JavaScript into your HTML?

Answer:

correct explanation using inline event handlers or inline code

Basic Javascript Array / XHTML Form Interview Question

Question

Are the following all equal, and, if so, what would your code look like to make the following all equal the same thing:

  alert(document.forms["myform"].elements["field"].value);
  alert(document.forms[1].elements[1].value);
  alert(document.myform.field.value);

answer:

<form name="myform" method="post" action="something">
<input name="anything" value="anything" type="something" />
<input name="field" value="something" type="something" />
</form>

Answer includes knowing that the form is the second form on the page, and that the field input element is the second element within that form.

 

JavaScript Interview Question

Question:

How do you dynamically add a paragraph with stylized content to a page?

Possible Answer:

newParagraph = document.createElement('p');
newParagraph.setAttribute('class', 'myClass');
newText = document.createTextNode('this is a new paragraph');
newParagraph.appendChild(newText);
myLocation = document.getElementById('parent_of_new_paragraph);
myLocation.appendChild(newParagraph);

 

Other questions ideas:

Q: How do you organize your CSS? How do you come up with id and class names (what naming conventions do you use)?
A: While there are no right answers, there are best practices. Issues to look for are not having div mania, no inline CSS, no presentational markup, minimal use of classes, understanding the CSS cascade.
Q: What do you think of hacks? When should you use them? If you use them, how do you maintain them? What can be done to avoid needing to use box-model hacks? (if they aren’t pros, you can ask them what is the issue with x-browsers and the box model)
Q: What are the pros and cons of using tables for layout? Do you use tables? What are the pros and cons of tableless design? How do you generally layout your pages?
A: check for them NOT using tables
Q: What are some deprecated elements and attributes that you use, and in what instances do you use them?
A: List of deprecated elements and attributes.
Q: What is involved in making a website accessible? What are arguments you use to convince others to invest in making their web site accessible.
A:  Making sites accessible also makes them more search engine friendly (saves money), makes your pages accessible to the 20% of the population that has some type of disability (so you can make more money) and it’s the law in many places.
Q: Define what web standards mean to you? How do you implement web standards?
Standardized specifications for Internet markup languages such as HTML, CSS, and XML. Formulated by the W3 organisation, these standards enable people to create websites that will work in almost any browser or internet-enabled device, instead of being specific to certain versions of Internet Explorer or Netscape Navigator.

Q: In CSS, how can you make a form elments background-color change when the user is entering text? will this work in all browsers?
It’s possible to change the default look of form elements by styling their html tags: inputselect and textarea.
but it won’t work in all browsers
Q: How can you target an element in your HTML using the DOM?
by using the nodes of the DOm elements we can target any element on any event in HTML
var gaJsHost = ((“https:” == document.location.protocol) ? “https://ssl.” : “http://www.”);
document.write(unescape(“%3Cscript src='” + gaJsHost + “google-analytics.com/ga.js’ type=’text/javascript’%3E%3C/script%3E”));
try {
var pageTracker = _gat._getTracker(“UA-1855756-5”);
pageTracker._trackPageview();
} catch(err) {}