“`TypeError`：使用IIFE时抛出`[0,1]`不是函数”

Question

Here is the code

 var numberArray = [0, 1] (function() { numberArray.push(2) function nestedFunction() { numberArray.push(3) function anotherNestedFunction() { numberArray.push(4) } console.log(numberArray) } })() 

I am expecting numberArray with value [0,1,2,3,4] but it is giving this error:

TypeError : [0,1] is not a function

Answer 1

var numberArray = [0, 1]
(function() {

is equivalent to

var numberArray = [0, 1] (function() {

That is where the error rise.

To resolve the issue place ; after the array declaration which JavaScript engine will consider both the line as separate statement:

 var numberArray = [0, 1]; (function() { numberArray.push(2); function nestedFunction() { numberArray.push(3); function anotherNestedFunction() { numberArray.push(4); } anotherNestedFunction(); console.log(numberArray); } nestedFunction(); })(); 

To ignore all these unexpected issue, it is always good practice to use semicolons ( ; ) after every statement in JavaScript.

Answer 2

Here is a working snippet

 const numberArray = [0, 1]; (function() { numberArray.push(2); (function nestedFunction() { numberArray.push(3); (function anotherNestedFunction() { numberArray.push(4); })(); console.log(numberArray); })(); })(); 

---

If you remove the ; after numberArray this is where you got a problem. You also have to use IIFE with your inner declared functions .

 const numberArray = [0, 1] (function() { numberArray.push(2); (function nestedFunction() { numberArray.push(3); (function anotherNestedFunction() { numberArray.push(4); })(); console.log(numberArray); })(); })();