Why do I need underscores in swift?

Question

Here it says, \"Note: the _ means “I don’t care about that value”\", but coming from JavaScript, I don\'t understand what that means.

The only way I can

Answer 1

Since Swift 3, specifying parameter names on function calls has become compulsory - even for the first. So, because that could cause huge problem to code written in swift 2, you can use a underscore at the declaration to prevent having to write the parameter name on call. So in this case, it is saying "don't care about the external parameter name". Where the external parameter name is what you call the parameters outside the function (on call) not inside. These external parameter names are called argument labels. http://ericasadun.com/2016/02/09/the-trouble-with-argument-labels-some-thoughts/ ... see how the parameter is given two names? well the first is where the underscore is going.Hope this helps, and do ask if still confused.