What’s the official javascript logo?
Is there an official JavaScript logo/icon or there is no official logo or icon at all? If not, which icon do you consider to be the most representative when referring to JavaScript? I am just curious, because PHP has an recognizable icon, perl has, ruby, python etc. all the other languages have some sort of official logo or icon.
There is probably no "official" icon, because there is no body officially "governing" JavaScript. See also this related Stack Overflow question about the "official" manual on JavaScript. Instead, JavaScript is a derivative of ECMAScript. Glancing over the official ECMAScript website I don't see any official logos or icons for ECMAScript either, not even in the specification documents (for version 3 nor for version 5).
Interestingly, the Wikipedia article on JavaScript showed in past this logo, which I'd personally never seen before:
In response to your second question: I guess if I must choose then I would go for any icon in my existing house style with these two features:
Capitals "JS"
Indication that the icon's about code