Discussion on: Arrow functions: a walkthrough and gotchas

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I recommend proof-reading the article as you have left in some typos and unfinished sentences:
e.g. NOW RETURN?! and it’s a niche thing and no one uses it even in obscure dev <- this sentence is not finished.

When discussing the arrow functions it is important to mention that it does not have its own this. So you can't bind these types of functions. Personally, I think you should use anonymous functions for small throwaway functions. Whenever you need reusable stuff you should aim to use the real, normal functions.

Also one more thing might have been mentioned and that is returning an object without the return keyword:

myArray.
  map(item => ({
    prop1: item.prop1 + item.prop2,
    prop2: item.prop3
  })
);

Or even adding destructuring to the mix:

myArray.
  map(({ prop1, prop2 }) => ({
    anotherProp1: prop1,
    prop2,
  })
);

Sylwia Vargas • Jul 9 '20 • Edited

Hi Andras! Thank you for taking the time to write this. I initially planned to talk about this, hoisting and function expressions, execution context, etc. but realized that:

this blog post is a beginning of a series called "js warm-ups" and is meant as supplement to helping people understand basic js concepts in a simple way;
the blog post was getting long and therefore, potentially overwhelming for people trying to just understand what the hell arrow functions are.

I decided to split it into two (or more), this one addressing the direct need of some of my students (expressed yesterday) and the other will be published when I have time to finish it later this week. Sadly, I entitled the blog before I finished it. Just bear with me :)

I did edit the post to include the two main gotchas, though.

András Tóth • Jul 10 '20

You are right, for beginners it must be scary. That's I think an inherent problem with the learning curve of JS: first it's very flat, then there's a huge uphill mountain to grasp all the quirks and gotchas (around function pointers, this and objects, immutability of Promises) and then it's very flat again.