To check if the String value is empty I am going to use isEmpty that Swift provides.
In the code example below I have two UITextFields which are called userNameTextField and userPasswordTextField. I first read the values that each UITextField contains and then check if these values are not empty.
// Read values from text fields let userName = userNameTextField.text let userPassword = userPasswordTextField.text // Check if required fields are not empty if (userName?.isEmpty)! || (userPassword?.isEmpty)! { // Display alert message here print("User name \(String(describing: userName)) or password \(String(describing: userPassword)) is empty") return }
If you are interested in video lessons on how to write Unit tests and UI tests to test your Swift mobile app, check out this page: Unit Testing Swift Mobile App
For more Swift code examples and tutorials, please check the Swift Code Examples page on this website.