Use regular expression in Swift String.contains() func

Question

In Swift, I have a String Variable thisString. I want to check to make sure the string contains only letters, numbers and/or dashes (-). Aside from doing this:

if ( thisString.contains("$") || thisString.contains("%") ) {
  //reject
} else {
 //accept
}

for each undesired character, which is ridiculous. I can't figure it out.

I would like to, in theory, do something like this with a regular expression:

if ( thisString.contains(regex([^a-zA-Z0-9-]) ) { 
  //reject
} else {
  //accept
}

Is this possible?

Answer 1

You are quite close

if thisString.range(of: "[^a-zA-Z0-9-]", options: .regularExpression) != nil { 
  //reject
} else {
  //accept
}

Update:

It becomes much more convenient with the new Swift Regex syntax (available in Swift 5.7+) where the syntax is pretty close to what you are looking for

if thisString.contains(/[^a-zA-Z0-9-]/) { 
  //reject
} else {
  //accept
}