Can you give an example of a situation where message dispatching mechanism is used?

The message dispatching mechanism in iOS is used, for example, when working with message queues in multithreaded programming.

Example: using DispatchQueue to perform tasks asynchronously.

When you need to update the UI from a background thread, message dispatching to the main thread is used:

DispatchQueue.global(qos: .background).async {
    // Perform background task
    let data = fetchData()
    
    DispatchQueue.main.async {
        // Update UI on the main thread
        self.label.text = data
    }
}

Here, the message dispatching mechanism ensures safe interaction between threads by sending tasks to the appropriate queues for execution.