Discussion on: Stop returning Null!

[Sergiu Mureşan]

That's actually an interesting solution. Abstracting that array to just a generic wrapper let's say (like the Nullable in C# or Optional in Java) it could work.

A few questions though:

• What do you do with arrays? Do you just .forEach(...).forEach(...)? Isn't that really difficult to read?
• What about properties on objects? let counter = {} and have to check for counter.elements to be instantiated.

My rule of thumb here is to never use null and simply check for undefined as my sole "none" value. So that if statement would be reduced to:

if (counter !== undefined) { ... }

And, if I know that counter has to be an object then I can simply do

if (counter) { ... }

Most JS programmers would recognize this pattern.

[Esteban Hernández]

I'm definitely for Generic Wrappers and these can be easily implemented with the above list strategies.

As for forEach(...).forEach(...), that will actually fail since forEach(...) is a consumer function; it doesn't return anything. Instead use map() which is the same as forEach() but it returns a value. I personally like to do stack method chains like so:

items
    .map(...)
    .filter(...)
    .map(...)
    .forEach(...);

That style blends well with list method chains, Promise chains and Streams.

I like the if (counter) style but this isn't going to work in every language and my employer doesn't allow it in our JS code. We have to always use the double check unfortunately.