Microsoft Javascript Problems

Internet Explorer has always had a "unique" (not a standards-compliant) way of interpreting JavaScript. As of IE8, most of these issues have been resolved, although there are still a couple of minor quirks. Fortunately, most of them are easily avoided.

<script type="application/javascript">

When putting a JavaScript into the head of an HTML document, the code must be surrounded by <script> tags. Most browsers support the value "application/javascript" for the "type" attribute, but IE8 does not. Instead, use "text/javascript" for consistent results across all browsers.

number.toFixed(0)

The number.toFixed(0) method should round to the nearest whole number. IE8 returns unpredictable results. Instead, use Math.round(number), as the result is consistent across all browsers.

selectElement(newOption, null).add()

In most browsers, the value "null" in this line of code adds "newOption" as the last option of a select element. In IE8, it gives the JavaScript error "Invalid Argument." The fix is simply to leave off the "null" argument when scripting specifically for IE8, as follows: selectElement(newOption).add().

References

• gtalbot.org: 64 Bugs in MSIE 8 for Windows
• javascripter.net: JavaScript Math Functions
• javascriptkit.com: Select and Options Objects