javascript - 未捕获的 TypeError : (intermediate value)(. ..) 不是函数

Question

当我在闭包中将 js 逻辑编写为单个 js 文件时，一切正常，如下所示:

(function(win){
   //main logic here
   win.expose1 = ....
   win.expose2 = ....
})(window)

但是当我尝试在同一个 js 文件中的闭包之前插入一个日志记录替代函数时，

 window.Glog = function(msg){
     console.log(msg)
 }
 // this was added before the main closure.

 (function(win){
   //the former closure that contains the main javascript logic;
 })(window)

它提示有一个TypeError:

Uncaught TypeError: (intermediate value)(...) is not a function

我做错了什么？

Answer 1

该错误是第三行缺少分号的结果:

window.Glog = function(msg) {
  console.log(msg);
}; // <--- Add this semicolon

(function(win) {
  // ...
})(window);

ECMAScript 规范有 specific rules for automatic semicolon insertion ，但是在这种情况下，不会自动插入分号，因为从下一行开始的带括号的表达式可以解释为函数调用的参数列表。

这意味着没有那个分号，匿名 window.Glog函数被调用，函数为 msg参数，后跟 (window)它随后试图调用返回的任何内容。

这就是代码的解释方式:

window.Glog = function(msg) {
  console.log(msg);
}(function(win) {
  // ...
})(window);