Validation of email in swift iOS application

Question

class func isValidEmail(testStr:String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
    let range = testStr.rangeOfString(emailRegEx, options:.RegularExpressionSearch)
    let result = range != nil ? true : false
    return result
}

I use this function to validate email in my login form. I can't understand how to rise this event from my textfield.

Using like this

if(username.isEqualToString("") || [!LoginController, testStr == self.username]) {
    self.dismissViewControllerAnimated(true, completion: nil)
    var alertView:UIAlertView = UIAlertView()
    alertView.title = "Sign in Failed!"
    alertView.message = "Please enter valid username"
    alertView.delegate = self
    alertView.addButtonWithTitle("OK")
    alertView.show()
    return
}

But getting unresolved error at teststr. I am new to Swift. Can any body explain me how to solve this?

Answer 1

Swift 4.2 and Xcode 10

For me, other answers were returning true if there are more then two dots after the domain name. I found this answer where it handles that condition properly.

func isValidEmail(testStr:String) -> Bool {
    let emailRegEx = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{1,4}$"
    let emailTest = NSPredicate(format:"SELF MATCHES[c] %@", emailRegEx)
    return emailTest.evaluate(with: testStr)
}

Happy Coding 😀

Answer 2

Apple Swift version 5.1.3 with Xcode 11.4

extension String {
    func isEmail()->Bool {
            let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}"
            return  NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: self)
    }
}

Use it :

 if let _textfieldText = textField.text {
            if _textfieldText.isEmail() {
                print("Okay Email go ahead")
            }else{
                print("Enter a valid email address first.")
            }
        }