What does this "(function(){});", a function inside brackets, mean in javascript? [duplicate]

Solution 1:

You're immediately calling an anonymus function with a specific parameter.

An example:

(function(name){
  alert(name);
})('peter')

This alerts "peter".

In the case of jQuery you might pass jQuery as a parameter and use $ in your function. So you can still use jQuery in noConflict-mode but use the handy $:

jQuery.noConflict()
(function($){
  var obj = $('<div/>', { id: 'someId' });
})(jQuery)

Solution 2:

You are making a function that is immediately being called, with someWord as a parameter.

Solution 3:

It's a way to define an anonymous function and then immediately executing it -- leaving no trace, as it were. The function's scope is truly local. The () brackets at the end execute the function -- the enclosing brackets are to disambiguate what is being executed.