Javascript function construct

Question

What does this construct mean?

var digits = [1, 2, 3];
(function fetchData(name){
 //body
})(digits.shift());

Answer 1

That syntax is used to prevent identifiers from leaking into the containing namespace.

After that code, if you attempt to call fetchData(name) you will find that fetchData is undefined, thanks to the () wrapper.

Answer 2

which construct?

I can explain what's happening, if that will help:

(in the order of execution)

1. array gets created and assigned the name of "digits"
2. the first element of "digits" gets removed from the array - so the length of the array gets reduced
3. that value that got removed gets passed as an argument into the function fetchData() as the variable "name"

Answer 3

Declare a function and call it.

Click on this http://jsfiddle.net/TC8K6/ you will see a alert of the parameter passed to the function.