Month: May 2012

Browser Performance/Capability Benchmark Testing

In the past few years the browser wars have heated up again. Performance and capabilities of some browsers varies greatly. There are several standard tests that are publicly available to benchmark your systems. WebKit (Safari, Chrome & Chromium) and Mozilla (Firefox) based browsers, as well as Opera perform pretty well, MSIE is currently trailing in most cases.

Here are a few common ones…

XHTML space slash

XHTML tags in the format <tag />.

<br />, <hr />, <img />, <input />, <base />, <link />

The space before closing slash was primarily done for legacy browsers that did not properly parse the value without an attribute or space, but does have some value in improving readability of XHTML markup. (In my experience this is NN4.x and earlier.)

Per http://www.w3.org/TR/xhtml1/#C_2:

C.2. Empty Elements

Include a space before the trailing / and > of empty elements, e.g. <br />, <hr /> and <img src="karen.jpg" alt="Karen" />. Also, use the minimized tag syntax for empty elements, e.g. <br />, as the alternative syntax <br /> allowed by XML gives uncertain results in many existing user agents.

REFERENCE:

JavaScript radix

The optional radix parameter for JavaScript parseInt(string,radix) function is often overlooked and can lead to some difficult problems when not specified. If you are in doubt, and only use/expect decimal numbers, you SHOULD set it to 10.

This might go undetected for a very long time, until someone decides to prefix their value with a zero or zero and an ‘x’ and your code interprets it with something completely different. This behavior can be different based on the browser used due to changes in the EcmaScript definition and support of ‘octal’.

Here’s why…

Radix can be any number from 2-36 to define the number system.

  • 2 = binary (0-1)
  • 8 = octal (0-7)
  • 10 = decimal (0-9)
  • 16 = hexadecimal (0-F, where… 0-9,A=10,B=11,C=12,D=13,E=14,F=15)

If the radix parameter is omitted, JavaScript assumes the following:

  • If the string begins with “0x” or “0X”, the radix is 16 (hexadecimal)
  • If the string begins with “0”, the radix is 8 (octal). This feature is deprecated
  • If the string begins with any other value, the radix is 10 (decimal)

In all cases, the following is observed:

  • Leading and trailing spaces are allowed,
  • If the first character cannot be converted to a number, parseInt() returns NaN.
  • Only the first number in the string is returned.

REFERENCES: