10th of 10 Questions.
What is an exclamation point in GraphQL?
In GraphQL, an exclamation point (!) indicates that a field in a query or a field argument is non-nullable. This means that the field must contain a value and cannot be empty. When used with a field, it ensures that the server always returns a value that is not null. When used with a field argument, it indicates that the client must provide the argument and it cannot be left out.