正则表达式不再起作用（Swift 1.2）

Question

I've been using:

    func isValidPassword(testStr2:String) -> Bool {
        println("validate password: \(testStr2)")

        let passwordRegEx = "[A-Z0-9a-z._%+-:/><#]{6,30}"

        if let passwordTest = NSPredicate(format: "SELF MATCHES %@", passwordRegEx) {
            return passwordTest.evaluateWithObject(testStr2)
        }

        return false
    }

to check that string has the appropriate characters. But since the swift 1.2 Update, I get an error saying "Bound value in a conditional binding must be of an Optional type"

I've tried adding question marks. But I can't find how to fix the problem. Anyone know what's gone wrong?

Answer 1

extension NSPredicate {
    convenience init(format predicateFormat: String, _ args: CVarArgType...)
}

is not a failable initializer anymore in Swift 1.2, so you cannot (and need not) test the return value with optional binding:

let passwordTest = NSPredicate(format: "SELF MATCHES %@", passwordRegEx)
return passwordTest.evaluateWithObject(testStr2)