Is there any tools/utilities to auto regenerate js content for release?

Question

Many websites, like Catch.com, depend on JavaScript heavily. Catch.com for example, when save the webpage, a javascript file: catchapp.js is downloaded, but it's content begins with strange codes, like:

function e(a) { throw a; } 
var i = void 0, j = !0, k = null, m = !1; 
function ba() { return function (a) { return a } } 
function ca() { return function () { } } 
function da(a) { return function (b) { this[a] = b } } 

So do they use some tools to change their js files before release?

Answer 1

They use JavaScript minification tools like jscompress. This will reduce the filesize, speed up the user's download and reduce bandwidth costs. It also works as code obfuscation.