How to check if UserDefaults object is Empty

This will be a guide to check if UserDefaults has been set.

You will want to use this to make sure a value is not nil before you use it.

Here is a simple example in a ViewController class.

1. Create a constant to interact with the UserDefaults
2. Create an if statement to check if the object does not exist.
3. If the object does not exist, then set a default option. In the gist above, I set it to dark.

There is no need to set the default option if the default object does exist because it has been set before.