Using a set to store malicious domains

maliciousDomainSetExample.swift

var badDomains: Set<String> = ["badguys.com", "drevil.me", "virus.io"]

let websiteToLoad = NSURL(string: "http://virus.io")
if let validDomain = websiteToLoad?.host {
    if badDomains.contains(validDomain) {
        print("This website is known to be malicious!")
    } else {
        print("This website doesn't exist in our dossier. Let's proceed.")
    }
}