reMekElek

function(
   a, // {Number}: random string length
   b, //         : internal variable: result
   c  //         : internal variable: char code
){
   for (
         b = ''; // result
         a--;    // random string length (arguments[0])
       )
         b += String.fromCharCode((                                  // http://www.w3schools.com/jsref/jsref_fromcharcode.asp