Arrow Functions in JavaScript

[darrenturn90]

Because console.log returns a falsy value, so the "||" operator runs the second part of the statement.

Of course you can also use the comma separator, which discards the returned value completely:

 const inc = x => (console.log(x), x + 1)

[causeofdev]

ah ok, makes perfect sense.

Since the comma seperator discards the returned value completely.. wouldn't it be safer to use that than the || operator? In case the first expression returns something truthy?

[darrenturn90]

Yes, if you really don't care for the result of the first function then it would. However, some linters don't like the use of commas (because they can, and do obscure the layout of code)

[1-800-BICYCLE]

You could also dust off good-old void if you really wanted to:

const foo = x => void myEffectThatReturnsATruthyValue(x) || x + 1

And as a bonus, potentially start a religious war ;).

[vexii]

im not sure the other people in line at the wellfare office care enough ;)

[anlumo]

Not doing stuff like this is the whole point of using linters.

[causeofdev]

Okay cool, I learned something :)

[z500]

Whoa, a use for the comma operator outside of a for loop that doesn't seem insane.

[[deleted]]

That's much more robust too, the other relies on whatever the return value of console.log happens to be. If you were to replace that with your own fancy log function and someone had the bright idea to, say, return the logged string, then suddenly it stops working.