立即调用函数表达式导致错误？

Question

Can someone explain why this could happen?

If I write something like this in a file named like test.js ,

const anyObject = {}
(function(){ 
  console.log('hello world!') 
}())

run it through console with $node test.js

then in the console, a hello world! will be printed, but followed with this: TypeError: (intermediate value) is not a function

Idon't know what exactly happend there, I guess somehow node is taking the function expression as a function call expression ?

I'm using node v6.9.1

Answer 1

You could use void for calling without semicolon.

This forces the expression to evaluate and return undefined .

 const anyObject = {} void (function() { console.log('hello world!') }()) 

It works even without outer parenthesis.

 const anyObject = {} void function() { console.log('hello world!') }() 

Answer 2

• Use semi colons
• Syntax is different in your IIFE

 const anyObject = {}; (function(){ console.log('hello world!'); })();