Anonymous functions in Javascript - why the indirection?

Question

I am going through the freecodecamp Javascript bootcamp. While I know the concept of anonymous functions and have extensively used them in C++, I am not able to understand the difference between the following two cases in Javascript:

Case A - This is how I first wrote an anonymous func in Javascript

const stats = {
  max: 56.78,
  min: -0.75
};

const half = (stats) => {
             return (stats.max + stats.min) / 2.0;
};

console.log(half(stats))

Case B - Freecodecamp has been using the following more extensively

const stats = {
  max: 56.78,
  min: -0.75
};

const half = (function() {
         return function half(stats) {
             return (stats.max + stats.min) / 2.0;
   };
})();

console.log(half(stats))

At first I thought this had something to do with recursion but that doesn't look like being the case.

I have tried both and both return the same result and both have the same call signature. Is there something additional about Case B or any use case where this might be required? Overall, how would I read this function? Like, for Case A, I could simply say that half is a function that takes stats as an input and returns some value

The second one is an IIFE used just to create the function. It doesn’t change the resulting function. — deceze
– deceze ♦, Commented Sep 6, 2021 at 5:54
Case B is return a function and execute it immediately with IIFE — ikhvjs
– ikhvjs, Commented Sep 6, 2021 at 5:55
Wanted to make sure that apart from the self-executing purpose, if there was anything else I was missing. Thanks for clarifying the details — aerialmyth
– aerialmyth, Commented Sep 6, 2021 at 6:11

vaira · Accepted Answer · 2021-09-06 05:55:10Z

1

Case B function is known as self-invoking/excuting function.

Here it is serving no purpose. self executing function

answered Sep 6, 2021 at 5:55

vaira

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