Ask HN: How often do you swap between languages ?

I was wondering how often people jump between various languages in a day and how it affects productivity.

In my case, I use Perl at work. I then jump to PHP, Python, and Javascript at home for personal projects almost on a daily basis. As an example, I have to google how to compute the length of an array if its :

1. strlen(myString)

2. myString.length()

3. myString.length

NB: I generally use Emacs for writing code in *nix/Mac and Notepad++ if on a Win Box.