Thought experiment around compression + gzip for http://www.456bereastreet.com/archive/201209/tell_css_that_javascript_is_available_asap/

gistfile1.md

Wondered what would happen if we tried to be more efficient about variable referencing. Turns out to not be a size savings after gzip, but might be infinitesimally faster to execute due to removing two property lookups.

Original:

document.documentElement.className = document.documentElement.className.replace(/(\s|^)no-js(\s|$)/, '$1' + 'js' + '$2');

121, gzips to 96 (20% smaller)

Compressed:

document.documentElement.className=document.documentElement.className.replace(/(\s|^)no-js(\s|$)/,"$1js$2")

107, gzips to 85 (20% smaller)

Rewritten:

(function(el) {
    el.className = el.className.replace(/(\s|^)no-js(\s|$)/, '$1js$2');
}(document.documentElement));

119, gzips to 115 (3% smaller)

Compressed:

(function(e){e.className=e.className.replace(/(\s|^)no-js(\s|$)/,"$1js$2")})(document.documentElement)

102, gzips to 102 (0% change)