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iOS Delegates in Swift 2 Delegation in iOS Modifying Behavior With Delegates

count the length of a String - Swift Delegate

Hi, in the video, count is done like this:

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
        let length = count(textField.text) - range.length + count(string) // but this error occurred: "Cannot invoke 'count' with an argument list of type '(String?)'"
        if length > 0 {
            submitButton.enabled = true
        } else {
            submitButton.enabled = false
        }
        return true
    }

what I do?

2 Answers

If you're using Xcode 7, you need to change 'count(textField.text)' to 'textField.text!.characters.count' and 'count(string)' to 'string.characters.count'.

Correct code for Xcode 8.1 is () func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { let length = (textField.text?.characters.count)! - range.length + string.characters.count if length > 0 { submitButton.isEnabled = true } else { submitButton.isEnabled = false } return true } ()

Please note that count(textField.text) has been changed to (textField.text?.characters.count)! in Xcode 8.1 and also 'submitButton.enabled' has been changed to 'submitButton.isEnabled'. Again it will be nice if put in teacher's notes.