Handle only else condition in swift 'if let' using 'where'

Question

I have a logic condition:

if let login = login where validateLogin(login) {
    // I'm not interested in this condition
} else {
    // This is interesting
}

Is there any option to write somehow if let condition to not handle true condition (because I dont want to do anything with that)? So, something like negation:

!(if let login = login where validateLogin(login)) {
    // This is interesting
}

Thanks for help.

Answer 1

The first branch in your if condition is actual made up of 2 criteria:

• if let is a check for non-null
• where is a syntactic sugar for a follow up condition, when you can be sure that the variable is not null.

You can reverse the logic like this:

if login == nil || !validateLogin(login!) {
    // do something
}