Today I learned to be wary of Javascript's parseInt() function when dealing with dates, among other things. It turns out that parseInt() evaluates strings starting with zero in base eight instead of base ten. So parseInt("01") produces zero. However, a radix parameter will account for this: parseInt("01", 10).
Javascript numbers are stored in IEEE-754 64-bit format. With bitwise operators, the number is converted into a signed 32-bit representation, and the conversion is very fast when compared with other math operations. Before I learned from Nicholas Zakas's book, High Performance Javascript, I stripped tables, lists, etc. with a modulus operation like most other code I've read. By using a bitwise "&" operation on a given number and the number one, when the number is even, the first bit is 0 and alternatively when the number is odd the result is 1.
I recently needed to add a close button to popups created with the BeautyTips jQuery plugin (BT). I of course did a cursory Google search to see if the use case had been solved before spending precious time delving into BT's source code (the requirement had been added minutes before the committee review meeting). No luck finding any solutions, but I did find the most tenacious forum poster I've ever encountered.
