Describe the Implications of Compound Data Types in Apex Programming. PLATFORM-DEVELOPER-II Practice Questions (Page 6)

Questions 26–29

1. 26application · medium

   A developer needs to store a matrix of integer values where each row can have a different number of columns. Which data structure is most appropriate?

   • AMap<Integer, Integer> matrix
   • BList<List<Integer>> matrix
   • CSet<Set<Integer>> matrix
   • DList<Integer> matrix
   Reveal Solution Discussion Select an answer first
2. 27expert · hard

   A developer is writing a batch Apex job that processes a large number of Account records. The job needs to update each Account's parent Account based on a custom field that stores the parent's external ID. The developer has a list of Account records with the external ID populated. To avoid hitting the SOQL query limit, which approach should be used?

   • AUse a List<Account> of parent Accounts and use the indexOf method to find the parent.
   • BQuery the parent Accounts inside the loop using the external ID.
   • CBuild a Map<String, Account> of parent Accounts keyed by external ID before the loop, then use it to set the ParentId.
   • DUse a Set<Account> of parent Accounts and check membership.
   Reveal Solution Discussion Select an answer first
4. 28application · easy

   A developer has a List<Integer> numbers = new List<Integer>{10, 20, 30, 40, 50}; and needs to remove the element at index 2. Which code snippet correctly removes the element?

   • Anumbers.removeAt(2);
   • Bnumbers.remove(30);
   • Cnumbers.remove(2);
   • Dnumbers.delete(2);
   Reveal Solution Discussion Select an answer first
5. 29foundation · easy

   Which characteristic is true for a List in Apex?

   • AElements are unordered and unique
   • BElements are ordered and can contain duplicates
   • CElements are key-value pairs
   • DElements are automatically sorted
   Reveal Solution Discussion Select an answer first