关于js自执行函数

1:

(function(window){ var qt = {}; qt.getSum = function(num1, num2) { return num1 + num2; } window.$qt = qt; })(window);

2:

!function(window){ var qt = {}; qt.getSum = function(num1, num2) { return num1 + num2; } window.$qt = qt; }(window);