Free practice test

GroupBy and Aggregates: Interview Practice

Ten interview-focused questions on grouping keys, comparers, aggregate correctness, buffering, ordering and report grain. Uses LINQ to Objects and C# 9 or later with the usual System, System.Collections.Generic and System.Linq imports. Unless stated, inputs are non-null and are not modified concurrently. Review the explained answers after submitting.

• Answers save as you go. Move between questions freely, and mark any to come back to.
• The clock starts when you begin, and the test submits itself at 00:00.
• Keyboard: press A–D to choose an option; ← and → move between questions.

Questions

10

Time

18 min

Right answer

+1

Wrong answer

0

10 marks in all

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