Enable a button in Swift only if all text fields have been filled out

Question

I am having trouble figuring out how to change my code to make it so the Done button in the navigation bar is enabled when my three text fields are filled out.

I cur

Answer 1

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    if (textField == self.textField1) { /* do Something */ }
    else if (textField == self.textField2) { /* do Something */ }
    else if (textField == self.textField3) { /* do Something */ }

    // regardless of what you do before, doneBarButton is enabled when all are not empty
    doneBarButton.enabled = (textField1.length != 0) && (textField2.length != 0) && (textField3.length != 0)
    return true

}