为什么节点中的 console.log(this) 返回一个空对象？

Question

When I ran console.log(this) in node it returns empty object

console.log(this)             // return { }

But when I used IIFE in node

(function printThisObject(){
   console.log(this);         // return the global object
})();

Can someone explain this to me ?

Answer 1

Because NodeJS runs your code in a module , and this references the object it creates for your module's exports (which is also the exports property on the module variable it provides you). (As they don't really mention that in the module documentation , I suspect using it is probably not a great idea — use exports instead.)

But your code calling the IIFE calls it with this referring to the global object, because in loose (non-strict) mode, calling a normal function not through an object property calls it with this set to the global object. (In strict mode, this would be undefined there.)