Use of unresolved identifier while using extension in swift 3

Question

I have made a String extension for validating the form in Swift 3 language. The code is below:

import UIKit
extension String {
    // Validating Email ID
    func isValidEmail(testStr:String) -> Bool {
        let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"
        let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
        return emailTest.evaluate(with: testStr)
    }
    // Validating the User name
    func isValidUserName(testStr:String) -> Bool {
        let RegEx = "\\A\\w{7,18}\\z"
        let Test = NSPredicate(format:"SELF MATCHES %@", RegEx)
        return Test.evaluate(with: testStr)
    }
    // Validating the phone number
    var isPhoneNumber: Bool {
        do {
            let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.phoneNumber.rawValue)
            let matches = detector.matches(in: self, options: [], range: NSMakeRange(0, self.characters.count))
            if let res = matches.first {
                return res.resultType == .phoneNumber && res.range.location == 0 && res.range.length == self.characters.count
            } else {
                return false
            }
        } catch {
            return false
        }
    }
    // validating the password 
    /*
    Use the function of Swift 3.0.
         1. 8 characters length
         2. alphabet
         3. special character
         regex Syntax Explanation :
         (?=.[a-z]) for Character.
         (?=.[$@$#!%?&]) for special character.
         {8,} for length which you want to prefer.
     */
    func isPasswordValid(_ password : String) -> Bool{
        let passwordTest = NSPredicate(format: "SELF MATCHES %@", "^(?=.*[a-z])(?=.*[$@$#!%*?&])[A-Za-z\\d$@$#!%*?&]{8,}")
        return passwordTest.evaluate(with: password)
    }
    // validating the password and confirm password are same........................
    func isPasswordSame(password: String , confirmPassword : String) -> Bool {
        if password == confirmPassword{
            return true
        } else {
            return false
        }
    }
    // validating Blank Text........................
    var  isBlank:Bool {
        return self.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines).isEmpty
    }
}

But when i am trying to use this extension class in other view controller through the code :

   if isValidEmail("kirit@gmail.com"){
            print("Validate EmailID")
        }
        else{
            print("invalide EmailID")
        }

I am getting the error:

Is think you want class func method, to call `String.isValidEmail("myString")`, or rather still instances ones `"myString".isValidEmail()`, but in both cases you may want to revise the declaration of the methods. Often, if you don't use `self` in an instance method, or one of its property, you may have thing wrong (forgot something, wrong design, etc.) — Larme, May 13 '17 at 21:13
You need to fix your extension because you don't need to pass any parameters when extending your type. — Leo Dabus, May 13 '17 at 21:15
check this http://stackoverflow.com/questions/31954416/regex-for-alphanumeric-without-special-characters-swift-ios/31954533#31954533 it might help you understand — Leo Dabus, May 13 '17 at 21:24

score 3 · Accepted Answer · answered May 13 '17 at 21:12

3

isValidEmail is not a loose function. You have defined it as an instance function on String. You would need to say

"someString".isValidEmail(testStr:"someOtherString")

That makes no sense, but that's how you've configured it. If you write it that way, your code will compile (though it will be very silly code).

answered May 13 '17 at 21:12

matt

515,959
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how to get it fixed my extension? – Jessica thompson May 13 '17 at 21:19
@JessicaRoot. You need to understand the difference between Instance and Class, and related topics Instance Methods vs Class Methods. It's a basic Oriented Object Programming topic. There should be question here on SO about that. Once you do, apply it in Swift. – Larme May 13 '17 at 21:22
I would have defined it as `func isValidEmail() -> Bool`, using `self` where you use `testStr`. – matt May 14 '17 at 00:24

score 0 · Answer 2 · answered May 13 '17 at 23:15

0

Just change your definition to something like

extension String {
// Validating Email ID
func isValidEmail() -> Bool {
    self.validate...
}

and then use it in your code as

@someString".isValidEmail()

answered May 13 '17 at 23:15

Russell

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Use of unresolved identifier while using extension in swift 3

2 Answers2