Categories
HTML PHP XML

PHP Interview Questions and Answers list

What are the Technology to Use for Parsing the XML ?
There are two types of XML parsers the we can use.
1. DOM (Document Object Module).
2. SAX (Simple API for XML).
DOM
The DOM (Document Object Model) extension allows to operate on XML documents through the DOM API with PHP 5. DOM is a standard defined by the W3C for accessing XML documents.
In PHP 4, DOM xml extension is not following the standard method names.
As per the new W3C compatibility, the old dom fxml-based scripts won’t work anymore. The API is quite different in PHP 5. But if we used the “almost W3C compatible” method names available in PHP 4.3, We only need to change the loading and saving methods, and remove the underscore in the method names. Other adjustments here and there may be necessary, but the main logic can stay the same. Though we have not used earlier so these will not be a problem for us.
The easiest way to read a well-formed XML file is to use the DOM library . The DOM library reads the entire XML document into an object and represents it as a tree of nodes,
SAX
SAX stands for Simple API for XML. It’s a callback-based interface for parsing XML documents. SAX support has been available since PHP 3 and hasn’t changed a lot since then. For PHP 5 the API is unchanged, The only difference is that it’s not based on the expat library anymore, but on the libxml2 library.
Rather than treating an XML document as a tree-like structure, SAX treats it as a series of events such as startDocument or endElement. To accomplish this, a SAX appllication consists of a parser that sends these events to “handlers,” methods or functions designated to handle them.
If you need a superfast forward only XML parser, you can use XMLReader. However you probably don\’t want a forward only parser.
If you want to read data from an XML file, the simple XML extension is probably the nicest solution. Also for creating XML, it might work well for you. Have a look at this article: http://devzone.zend.com/node/view/id/688
If you want a superfast forward only XML writer, use XMLWriter. You could also do this by just outputting the XML of sticking it all together in a string. But the XMLWriter will make your code clearer, automatically escape stuff and give some error indications.
How can we get second of the current time using date function?  what is Magic methods in php?

There are seven special methods, and they are as follows:
__construct( )  Called when instantiating an object
__destruct( ) Called when deleting an object
__get( ) Called when reading from a nonexistent property
__set( ) Called when writing to a nonexistent property
__call( ) Called when invoking a nonexistent method
__toString( ) Called when printing an object (for eg: converting an object to strings)
__clone( ) Called when cloning an object (copying object)
There are actually 12 special methods at last count
The function names __construct, __destruct (see Constructors and Destructors), __call, __get, __set, __isset, __unset (see Overloading), __sleep, __wakeup, __toString, __set_state and __clone
http://us2.php.net/oop5.magic
what is scandir() ?

List files and directories inside the specified path By default files order will be ascending
$f = scandir($direct, 1); it will display the files as descending order
Which types of form elements can be excluded from the HTTP request?
A. text, radio, and check box
B. text, submit, and hidden
C. submit and hidden
D. radio and check box

Answer D is correct.
When not selected, both radio buttons and check boxes are excluded from the HTTP request. Answer A, C, B are incorrect because they are always included in the request.

 Is PHP a case sensitive programming language?
 PHP is a partially case sensitive programming language. We can use function names, class names in case insensitive manner.
What is mean by LAMP?
 LAMP means combination of Linux, Apache, MySQL and PHP.
 How do you get the user’s ip address in PHP?
 Using the server variable: $_SERVER[’REMOTE_ADDR’]
 What is the difference between require and include?
 When using require function to embed another file in php, it will give fatal error if the file is not exists.
 When using include function to embed another file in php, it will give warning if the file is not exists.


How to find the number of elements in an array?

 Using count($array) or sizeof($array).
 How do you make one way encryption for your passwords in PHP?
 Using md5 function or sha1 function
 How do you get ASCII value of a character?
 By using ord function.

Categories
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) {}