GraphQL Interview Questions and Answers
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Ques 26. What is the role of the `@deprecated` directive in GraphQL?
The `@deprecated` directive in GraphQL is used to mark a field or enum value as deprecated. It provides information to clients about the deprecation and suggests an alternative field or value to use.
Ques 27. How does GraphQL handle null values in responses?
In GraphQL, null values are used to represent the absence of a value for a field. Fields can be explicitly marked as nullable or non-nullable using the `!` (exclamation mark) in the type definition.
Ques 28. What is the purpose of the `fragment` keyword in GraphQL?
The `fragment` keyword in GraphQL is used to define reusable sets of fields that can be included in queries. Fragments help in organizing and reusing common field selections across multiple queries.
Ques 29. Explain the concept of DataLoader in GraphQL.
DataLoader is a utility in GraphQL that helps in batching and caching database queries. It is commonly used to address the N+1 query problem by efficiently loading data in batches.
Ques 30. What is the purpose of the `fetchPolicy` option in Apollo Client for GraphQL?
The `fetchPolicy` option in Apollo Client allows developers to control how queries are fetched and updated. It provides options like 'cache-first,' 'network-only,' and 'no-cache' to customize the caching behavior.
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