Check if string is 3 chars and 3 number in Swift

I'm trying to create a function that validate my string if it is using this format

ABC123
First three characters should be letters and the other 3 should be numbers

I have no idea on how to start

Thanks

You can do it with a regular expression match on strings, like this:

    let str = "ABC123"
    let optRange = str.rangeOfString("^[A-Za-z]{3}\\d{3}$", options: .RegularExpressionSearch)
    if let range = optRange {   
        println("Matched")
    } else {
        println("Not matched")
    }

Regex above requires that the match occupied the whole string (the ^ and $ anchors at both ends), has three letters [A-Za-z]{3} and three digits \\d{3}.

You can also use it as an extension if you would like to:

    extension String {
        var match: Bool {
            return rangeOfString("^[A-Za-z]{3}\\d{3}$", options: .RegularExpressionSearch) != nil
        }
    }


    "ABC123".match // true