To put it in simple words, if you use any operator ( () - grouping op. or ! unary not ) on the function it becomes a "function expression", as opposed to a "function statement".
A line that starts with the function operator is a function statement (declaration). By definition, a function declaration can not be self executed. See here for more info: https://developer.mozilla.org/en/JavaScript/Reference/Functions_and_function_scope HTH, ~Y On Sep 29, 1:18 pm, Lasse Reichstein <reichsteinatw...@gmail.com> wrote: > On Thu, Sep 29, 2011 at 2:17 AM, Jimmy Chan <jimmyhc...@gmail.com> wrote: > > some claim the ! has better performance over () > >http://jsperf.com/bang-function > > > from > >http://stackoverflow.com/questions/5827290/javascript-function-leadin... > > That difference seems to be below the noise level. > In Chrome 16, Opera 11.51 and IE 9, the different approaches are about the > same speed (with +/- being markedly slower in Chrome and Opera, probably > due to actually doing the to-number conversion, hitting NaN and getting > penalized for that by the FPU). > > Seehttp://jsperf.com/bang-function/2 > Always run the tests twice and take the second result. That ignores the > warmup effect on the test suite itself that might otherwise affect earlier > tests negatively. > > /L -- To view archived discussions from the original JSMentors Mailman list: http://www.mail-archive.com/jsmentors@jsmentors.com/ To search via a non-Google archive, visit here: http://www.mail-archive.com/jsmentors@googlegroups.com/ To unsubscribe from this group, send email to jsmentors+unsubscr...@googlegroups.com
