IF Browsers were women

reference: sharenator

Problems with JS for...in Loop

Sometimes on pleasant mornings when you have got all the reasons to smile your code breaks down suddenly and your Page contains errors n errors.
Similar thing happen to me recently.
My webpage was full of JS errors on one fine morning.
I just could understand why..... but again google came to my rescue.
I found this article.... about dangers of using for...in loop

The Problem

Try the following code on an empty page, one without any JavaScript libraries added:

var associative_array = new Array();
associative_array["one"] = "Lorem";
associative_array["two"] = "Ipsum";
associative_array["three"] = "dolor";
for (i in associative_array) { alert(i) };

You’ll get three sequential alert boxes: “one”; “two”; “three.” This code has a predictable output and looks logically sound: you’re declaring a new array, giving it three string keys, then iterating over them.

Now do this: replace “Array” with “RegExp” and run the code again. As if by magic, this also works! It’s not the only one. Try Boolean, or Date, or String, and you’ll find they all work as well. It works because all you’re doing is setting properties on an object (in JS, foo["bar"] is the same as foo.bar), and a for..in loop simply iterates over an object’s properties. All data types in JS are objects (or have object representations), so all of them can have arbitrary properties set.

In JavaScript, one really ought to use Object for a set of key/value pairs. But because Array works as demonstrated above, JavaScript arrays (which are meant to be numeric) are often used to hold key/value pairs. This is bad practice. Object should be used instead.

I’m not trying to ridicule or scold. This misconception is too common to attribute it to stupidity, and there are many legitimate reasons for the confusion. But this is something that needs to be cleared up if JavaScript is ever to be used on a grand scale.

If you need further evidence that Array is not meant to be used this way, consider:

• There is no way to specify string keys in an array constructor.
• There is no way to specify string keys in an array literal.
• Array.length does not count them as items. In the above example, associative_array.length will return 0.
• The page on Arrays in the Mozilla JavaScript reference makes no mention of this usage. (Nor does the ECMAScript specification, by the way, but you’ll have to do your own legwork to verify that, because I’m not linking to page 88 of a kajillion-page PDF.)

The History

This confusion has several other contributing factors:

• In PHP, a language that many JavaScript users are also familiar with, numeric arrays and associative arrays are treated more or less identically. And since a set of key/value pairs goes by about eleven different names, depending on the language, this usage is quite often a result of unclear definitions of terms.
• JavaScript is interpreted, not compiled, and many people have learned it by example. Thus a third-party script that uses Array improperly might rub off on its users.
• JavaScript started with no specification, then received a poor specification, and I know few people who spend their free time reading specifications. Especially bad ones.
• Because there is no formal construct for key/value pairs, JavaScript cannot distinguish between creating a hash and setting properties on an object. As we’ve demonstrated, any object can have arbitrary properties, and a for..in loop simply iterates over each of these properties, so the code above is not explicitly incorrect.
• The harmful side effects of using Array for key/value pairs are not experienced unless Array.prototype is extended. Since this is an underutilized feature of JavaScript, it hasn’t been done on a large scale until rather recently.

Why Prototype “breaks” this usage

Concurrent with Prototype’s rise in popularity have been various blog posts complaining that the JavaScript framework “breaks” associative arrays — i.e. Arrays with string keys. It “breaks” them because it adds a handful of useful methods for working with arrays to Array.prototype, and these methods are also iterated over in a for..in loop. This means that when Prototype is included on a page the code above will loop 35 times instead of the original three.

Prototype also extends String with some methods for dealing with strings. If you try to use String as an associative array, your code will loop 20 times instead of three.

I am aware of the mitigating factors — hell, I just enumerated them — but complaining that Prototype “breaks” your ability to use Array as a hash is like complaining that Prototype “breaks” your ability to use String as a hash. It is not Prototype’s fault that JavaScript does not deter this improper use, and it certainly does not mean that Prototype does not “play well with others.” You are free to reject Prototype and keep using Array improperly, but then you give up your right to bitch and moan.

Actually, we’ve been here before: before version 1.4, Prototype added a couple methods onto Object.prototype, meaning that Object couldn’t even be used in the manner I describe, and a bunch of people rightly took Sam Stephenson to task for it. Object.prototype is verboten. Since version 1.4, however, this is no longer an issue, and therefore there is no longer an excuse.

So I will say it again: Array is not meant to be used for key/value pairs. Luckily, there is a dead-simple way to fix this. In the above example, you need only change Array to Object. (Or, if you’re using literal syntax, change [] to {}.) There. Your wrong code is no longer wrong, and it took only a little more work than a simple find-and-replace.

There are plenty of JavaScript frameworks to choose from, and many of them are excellent. I use Prototype because it works for me, and I do not take it personally when other people decide they don’t like it. But I believe Prototype deserves to be hated on its merits, dammit, not because it makes wrong code stop working — especially when the wrong code can be made right in ten seconds.

The Guru's

This image is posted here coz all these Guru's (Father's) have influenced me in some point of time.

Web Developers Link Farm

Recently I found this cool link [ http://www.devlisting.com/ ] which displays all useful links that can be referred during Web Development. Its a resourceful link farm.
Some of the link categories of this farm contains are listed below:

• Ajax
• Firefox Plugins
• Ruby
• Traffic / SEO
• Flash
• Asp.net
• Design

Go here http://www.devlisting.com/

Navigation Without Mouse Clicks

Have you ever wondered how Surfing would be without mouse-clicks.
Still thinking what I mean.
Let me make it straight then.
lets Say there exist a "Link". Now inorder to view this page, people would normally click it.
Navigating without mouse clicks is that -all we need to do is just do mouseover on it and the link will be clicked and we will be taken to the desired page.

This is very much possible and many research projects are made online based on No-Click Idea.
If this idea is accepted by Internet Users then there would be no sound of mouse clicking while surfing internet,it would be a Quite expedition and number of people complaining of finger pains due to mouse clicks will also gradually decrease ;).

One such research project is here .
Its www.dontclick.it

I would strongly recommed you all to visit it so as to get that weird-nice experience while navigating this site.

I thoroughly enjoyed my experience and even played few games there.

Search Engines

These days most search engines will automatically index your web page.But if you are interested to do it manually, here is a list of few popular search engines wherein you can feed in your web page address ;)

Search Engines that will accept your URL


Google http://www.google.com/addurl.html
Yahoo! http://docs.yahoo.com/info/suggest/
Altavista http://www.altavista.com/addurl/
AllTheWeb http://www.alltheweb.com/add_url.php
Dmoz http://www.dmoz.org/help/submit.html
Webcrawler http://www.webcrawler.com
Dogpile http://www.dogpile.com
MetaCrawler http://www.metacrawler.com
LookSeek http://www.lookseek.com

Web Glossary

This is a short glossary list for some commonest and few lesser known terms used over www.

Web Glossary

ActiveMovie
A web technology for streaming movies from a web server to a web client. Developed by Microsoft.

ActiveX
A programming interface (API) that allows web browsers to download and execute Windows programs.

Amaya
An open source web browser editor from W3C, used to push leading-edge ideas in browser design.

Archie
A computer program to locate files on public FTP servers.

API (Application Programming Interface)
An interface for letting a program communicate with another program. In web terms: An interface for letting web browsers or web servers communicate with other programs.

Banner Ad
A (most often graphic) advertisement placed on a web page, which acts as a hyperlink to an advertiser's web site.

Baud
The number of symbols per second sent over a channel.

Clickthrough Rate
The number of times visitors click on a hyperlink (or advertisement) on a page, as a percentage of the number of times the page has been displayed.

Cookie
Information from a web server, stored on your computer by your web browser. The purpose of a cookie is to provide information about your visit to the website for use by the server during a later visit.

ColdFusion
Web development software for most platforms (Linux, Unix, Solaris and Windows).

Dynamic IP
An IP address that changes each time you connect to the Internet.

Gateway
A computer program for transferring (and reformatting) data between incompatible applications or networks.

Hits
The number of times a web object (page or picture) has been viewed or downloaded.

Trojan Horse
Computer program hidden in another computer program with the purpose of destroying software or collecting information about the use of the computer.

Spoofing
Addressing a web page or an e-mail with a false referrer. Like sending an e-mail from a false address.

Web Spider
A computer program that searches the Internet for web pages. Common web spiders are the one used by search engines like Google and AltaVista to index the web. Web spiders are also called web robots or wanderers.

Worm
A computer virus that can make copies of itself and spread to other computers over the Internet.


Exhaustive list of glossary is available here

Google results Incomplete

While playing around with Google, I found that although Google claims it has returned lakhs of entries for your search it never shows more than 1000 entries.

check this link out

http://www.google.com/search?q=google&hl=en&rls=WZPA,WZPA:2006-37,WZPA:en&start=990&sa=N

this is the last page of the results for search keyword google.

and at the bottom it shows

If the above link is clicked to fetch omitted results, google doesn't shows all those records instead it repeats the same query and displays only till 1000 entries.

Strange fact is all the other search engines like Yahoo, ninemsn, ask, msn, etc all behave the same as Google. Nobody displays all the records.