¿Cómo crear un cuadro de diálogo de alerta en Swift?

How to create an alert dialog in Swift?

An alert dialog in Swift is created using a UIAlertController class. The below Swift code snippets demonstrate how to: Create a new alert message using UIAlertController, How to add one or more action buttons and how to handle button events, You will also learn how to change the UIAlertController style.

Before we dive into Swift’s ways you can find items in an array, let’s find out how such an algorithm actually works. This will definitely help your understanding of algorithms and iOS development in general. When you’re learning iOS development, it’s a great idea to set aside some time to learn how commonly used algorithms work.

The constructor of UIAlertController takes three arguments: a title, a description and an alert controller style. Then, you’re adding two actions to the alert: Yes and No. More on actions later. Finally, you’re presenting the alert by calling the function present (_:animated:) on self. This will display the alert to the user.

Because the firstIndex (of:) function searches an array from front to back, it’ll always return the index of the first match it finds. If you want to get the last match in an array, you can use the lastIndex (of:) function.

This means that the user will not be able to dismiss it. See the next code snippet to learn how to add action buttons. The above Swift code snippet creates and displays an alert message but it does not contain any action buttons and thus the user will not have any means to dismiss it.

The .destructive style is usually red, indicating to your app’s users that this is a dangerous action or one that cannot be undone. Note: Even if you change the order of adding the actions to the alert, the Cancel button is always shown first. The UIAlertController can also have a preferred action.