macos - 条件绑定(bind)中的电子邮件验证绑定(bind)值必须是可选类型

Question

我有下面的代码来检查字符串是否是有效的电子邮件。更新到 Swift 1.2 后，我现在看到错误:

Bound value in a conditional binding must be of Optional type 

在线

if let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx) 

我不确定应该如何消除此错误。有什么建议吗？

谢谢

 func isValidEmail(testStr:String) -> Bool {
        println("validate calendar: \(testStr)")
        let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"

        if let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx) {
            return emailTest.evaluateWithObject(testStr)
        }
        return false
    }

    println("Email is: \(isValidEmail(email))")

Answer 1

将您的功能更改为:

func isValidEmail(testStr : String) -> Bool {
    println("validate calendar: \(testStr)")
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"       

    let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)

    if emailTest.evaluateWithObject(testStr) {
        return true
    }
    return false
}

或者您也可以将其更改为:

var emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)        
var result = emailTest.evaluateWithObject(testStr)        
return result

而且也应该工作。希望对您有所帮助。