Question

In this post, Nick Craver provided an answer in which he used:

function(_, id)

This code doesn’t declare the underscore as a variable before using it. My search on google and on here only points to references to the use of the underscore as a prefix., not as the variable itself. What does it do? I like the solution by Nick but that bit bothers me.

Answer 1

I’ve seen the underscore used to denote that the variable is a "don’t care" variable. It means that it doesn’t matter and isn’t used at all.

In the case you pointed out, it was used to signify that his function had two arguments, but they only needed the second one.