user2722667 user2722667 - 27 days ago 9
Swift Question

Swift 2 unused constant warning

I am getting a warning saying my constant is unused:


Initialization of immutable value 'myConst' was never used; consider replacing with assignment to '_' or removing it


if someVal["value"] != nil {
let myConst = someVal["value"]
}


So what will renaming
let myConst = someVal["value"]
into
_ myConst = someVal["value"]
do/mean?

Answer

You're not replacing let with _, but you're replacing the variable name with it. If the variable isn't used anywhere in the code it's irrelevant so the line can be written like:

_ = someVal["value"]

If you want to use it somewhere you need a name for it to reference it later on. But when you don't use it writing _ is a lot easier ...