Chapter 13 – GraphQL Fundamentals

1. It depends on the use cases. However, it performs much better for mobile apps and web-based UI applications.
2. Fragments should be used while sending a request from the GraphQL client when the response contains an interface or union.
3. You can use a variable in a GraphQL query/mutation as shown next. You are going to modify the GraphQL request sent in step 6 of the Testing GraphQL Query and Mutation section:

   mutation removeStar ($repoId: String) {
     addStar(input: {
       starrableId: $repoId
     }) {
       clientMutationId
     }
   }

4. Here, you can see that the $repoId variable is used. You have to declare that variable in the named mutation and then you use it in the mutation's argument as shown in the following code block:

   {
     "repoId": "MDEwOlJlcG9zaXRvcnkyOTMyOTU5NDA="
   }