About.com Focus on JavaScript

Getting Rid of document.write

Tue, 09 Feb 2010 05:41:25 +0000

The document.write statement was a big part of being able to use JavaScript to update web pages back when JavaScript was first created. Modern web browsers provide much better less obtrusive ways of doing the same updates. Here are some instructions on how you can update your web pages to replace the document.write statements with innerHTML calls instead which will allow you to consolidate all your scripts to the bottom of the page instead of having scripts scattered throughout the HTML.

Getting Rid of document.write

Getting Rid of document.write originally appeared on About.com Focus on JavaScript on Tuesday, February 9th, 2010 at 05:41:25.

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The Bad Parts of JavaScript

Mon, 08 Feb 2010 08:06:13 +0000

JavaScript includes a number of constructs that have either been superseded by something better or which seemed like a good idea to those who created JavaScript in the first place but which have turned out to be more trouble than they are worth. Here are some of the JavaScript constructs you should avoid as well as some that can be problematic if not used properly (so you should avoid them where possible as well).

The Bad Parts of JavaScript

The Bad Parts of JavaScript originally appeared on About.com Focus on JavaScript on Monday, February 8th, 2010 at 08:06:13.

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Back References

Sun, 07 Feb 2010 16:58:49 +0000

The fifteenth tutorial on Regular Expressions introduces Back References - this is a way to refer back to a previous section of the string that you have already matched to the pattern. Any section of the string that is matched by a group is automatically added to an array of back references.

Back References

Back References originally appeared on About.com Focus on JavaScript on Sunday, February 7th, 2010 at 16:58:49.

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JavaScript and Emails

Sat, 06 Feb 2010 08:02:47 +0000

Email programs are very different to Web Browsers regarding JavaScript. One format that most email programs support to send emails in is HTML. Just because you can use HTML in emails though doesn't mean that you can also use JavaScript as well. Yes some email programs do support JavaScript but there are some very good reasons why you should disable JavaScript in your email program if it hasn't already done that for you.

JavaScript and Emails

JavaScript and Emails originally appeared on About.com Focus on JavaScript on Saturday, February 6th, 2010 at 08:02:47.

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Javascript and XHTML

Fri, 05 Feb 2010 16:04:47 +0000

XHTML treats embedded Javascript code slightly differently from the way HTML does. You need a small piece of extra code to get them working together properly. Of course you will not have to worry about this if you keep the JavaScript in a separate file.

JavaScript and XHTML

Javascript and XHTML originally appeared on About.com Focus on JavaScript on Friday, February 5th, 2010 at 16:04:47.

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Unobtrusive Random Images

Thu, 04 Feb 2010 08:09:20 +0000

One of the first things most old books on JavaScript used to teach was selecting a random image to display in a set spot in your web page. Such scripts are easy to write, easy to explain in a book or tutorial, and very hard to alter when you want to make changes to the way it works.

An unobtrusive script to do the same thing is slightly harder to write since you need to understand how the DOM works so as to update the page with your randomly selected image. The script is much easier to update when you want to add additional functionality since the JavaScript is already completely separate from the HTML and it is already using the DOM to add the image. My unobtrusive random image script not only allows you to add one or more random images to your web page by just adding one line of JavaScript for each additional image to be displayed, it also allows you to have the images automatically replaced every so many seconds with just one additional line of code.

Unobtrusive Random Images

Unobtrusive Random Images originally appeared on About.com Focus on JavaScript on Thursday, February 4th, 2010 at 08:09:20.

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Alternate Script Tag Location

Wed, 03 Feb 2010 09:25:47 +0000

In the examples so far in the "Learn Modern JavaScript" series I have shown the script tag in thee head of the web page with code in it to ensure that parts of the page are loaded before they are referenced. There is an alternate location that simplifies the code but which has other implications on how your page will load.

Alternate Script Tag Location

Alternate Script Tag Location originally appeared on About.com Focus on JavaScript on Wednesday, February 3rd, 2010 at 09:25:47.

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location Reference

Tue, 02 Feb 2010 09:42:30 +0000

JavaScript can interact with the address of the current page. The location object provides JavaScript with not only access to read the various pieces of information from the current page address but also allows you to change those values and hence to load a new page.

location Reference

location Reference originally appeared on About.com Focus on JavaScript on Tuesday, February 2nd, 2010 at 09:42:30.

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Browser Object Model

Mon, 01 Feb 2010 08:16:13 +0000

This part of JavaScript is the part that doesn't have a standard and so while some of the information provided about the browser are supplied the same way by all browsers, much of the most useful information is not. This summary will help you see what parts of the BOM do and don't have a defacto standard and how to make your own functions to get the useful information that don't have a standard access method.

Browser Object Model

Browser Object Model originally appeared on About.com Focus on JavaScript on Monday, February 1st, 2010 at 08:16:13.

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Grouping

Sun, 31 Jan 2010 16:50:55 +0000

Up until now we have looked at regular expressions involving single characters and repetitions of single characters. The fourteenth tutorial on regular expressions introduces you to a way to group characters together allowing you to test for repeating groups.

Grouping

Grouping originally appeared on About.com Focus on JavaScript on Sunday, January 31st, 2010 at 16:50:55.

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