Most Important GraphQL And Apollo Client MCQS

GraphQL is a query language for API’s.It is a runtime for fulfilling those query’s with your existing data. GraphQL provides a complete description of the data in your API. It gives clients the power to ask for exactly what they need and nothing more, makes it easier to evolve APIs over time, and enables powerful developer tools.

• What are the valid graphQL operation?
  a. Query
  b. Mutation
  c. Subscription
  d. All of these

View Answer

• Working with GraphQL has following major advantages.
  a. No Overfetching
  b. Single source of truth
  c. Typed Query Language
  d. Declartive data fetching
  e. All of the operation

View Answer

• Apollo provides only client side libraries support and not for the server side.
  a. True
  b. False

View Answer

• Apollo’s ecosystem is stable for other major languages as well.
  a. True
  b. False

View Answer

• Apollo uses below operation to fetch data from server.
  a. Query
  b. Mutation

View Answer

• GrapgQL “fragments” are used to share common fields in multiple operation.
  a. True
  b. False

View Answer

• There is a limitation in “fragments”. We can share pieces of logic for “queries” only but cannot for “mutation”.
  a. True
  b. False

View Answer

• Variables in grapgQL starts with “$” sign
  a. True
  b. False

View Answer

• We use below sign to make fields mandatory/not null in GraphQL.
  a. $
  b. —
  c. !
  d. @
  e. None of the option

View Answer

• Data graph uses a “Schema” to define data and its type.
  a. True
  b. False

View Answer

• For every “query”. We need to write its resolver function.
  a. True
  b. False

View Answer

• “ApolloProvider” wraps the whole React app so that we can access it from anywhere throughout the app
  a. True
  b. False

View Answer

• What is the correct syntax to use the “ useQuery” hook in react?
  a. Cont{ loading, error,data} =useQuery(GET_LIST)
  b. Cont { data, error, loading} =useQuery(GET_LIST)
  c. Const {error, data, loading} = useQuery(GET LIST)
  d. None of the options

View Answer

• What is the correct syntax of using the “useQuery” hook along with variable.
  (“GET _LIST” is a constant containing a gql query)
  a. Const{ loading, error, data} = useQuery(GET_LIST {variable {fruits, “Mango”}})
  b. Const{ loading, error, data} = useQuery({variables (fruit, “Mango”},)GET_LIST)
  c. Const{ loading, error, data} = useQuery(GET_LIST, {variables {fruit, “Mango”}})
  d. None of the option

View Answer

• What is the correct syntax of using the “useMutation” hook in react?
  a. Const[addTodo,{data}] = useMutation(ADD_TODO);
  b. Const{addTodo, data} = useMutation(ADD_TODO);
  c. Const[addTodo, data ] = useMutation(ADD_TODO)
  d. None of the options

View Answer

• We use “subscritions” operation to get live event updates from server
  a. True
  b. False

View Answer

• Apollo client supports the following error policies for an..
  a. Ignore
  b. None
  c. None of these

View Answer

• This is not possible to update “Headers” in graphQL requests
  a. True
  b. False

View Answer

• It is a beauty of graphQL subscriptions that it does not uses “pub/sub” pattern
  a. True
  b. False

View Answer

• Apollo client store the results of its queries in the following way.
  a. In memory cache
  b. Database
  c. Local File
  d. Apollo cache

View Answer

• Which of the following pattern is used GraphQL’s Subscription.
  a. Pub/sub
  b. Request/response
  c. Streaming
  d. None of the options

View Answer

• Which of the following GraphQL’s hooks
  a. useQuery
  b. useLazyQuery
  c. useQueryLazy
  d. None of these

View Answer

• Which of the following GraphQL’s hooks should be used to update data on server
  a. useQuery
  b. useMutation
  c. useSubscription
  d. none of the options

View Answer

Read More: Most Important React JS Interview Questions and Answers 2021