Does Google read external Javascript Files that are included

Does Google read external Javascript Files that are included?

If I were to append non-keyword information using jquery or such would this affect keyword density?

Now I would normally stick to plain HTML/CSS generally but I am curious about this, has anyone tested this before or know factually not I THINK but know or ha开发者_如何学JAVAve some evidence behind them?

Any external content you add dynamically to your web page (via javascript/jquery) will NOT be parsed by the search engines.

Be careful: Too much "keyword rich" will hurt you.