Final Quiz: 15 Questions on C# From First Program to Confident Developer

How this quiz works

• 15 multiple-choice questions, one correct answer each, drawn from the whole course: first programs, values and input, loops, methods, collections, text, classes, records, files, LINQ, async, pattern matching, events and concurrent tasks.
• Timed mode: 20 minutes. Answer every question before you check a single result.
• Online version: Final Quiz: C# From First Program to Confident Developer: 15 questions, 20 minutes, scored automatically (free).
• Scoring: 1 point for each right answer, no negative marking. Pass: 9 of 15 (60%).
• Code questions were compiled and run on .NET 10 with warnings treated as errors. Every answer explains its reasoning and links to the lesson that teaches it.
• The quiz is free. It is a check of what you have learned, not an interview simulation.

Before you start: five warm-up checks

Answer these on paper first. They are different from the quiz questions.

W1. dotnet build succeeds. Does that prove the program meets its requirements?

W2. A loop is while (remaining > 0) and remaining starts at 0. How many times does the body run?

W3. A method returns a value but the caller writes AddFive(minutes); on its own line. What happens to the result?

W4. You need a sequence that grows and shrinks as tasks are added and removed. Which collection is the usual starting choice?

W5. A CancellationTokenSource is cancelled after a save has already finished. Is the save undone?

Warm-up answers

• W1. No. A successful build only means the code compiled. Run the program and check its output against the requirements. (Lesson 1)
• W2. Zero times. A while loop checks its condition before the first pass. (Lesson 3)
• W3. It is discarded. A return value goes back to the caller and is not assigned anywhere unless you store it. (Lesson 4)
• W4. List<T>. Use an array for a fixed number of elements and a dictionary for lookup by key. (Lesson 5)
• W5. No. Cancellation is a cooperative request. It does not undo side effects that have already completed. (Lessons 13 and 18)

What the quiz covers

Area	Lessons
Output, expressions, parsing versus validation	1, 2
Loops and methods	3, 4
Collections, text and null	5, 6
Classes, records and equality	7, 8
Files, LINQ and async	10, 12, 13
Pattern matching, events and concurrent tasks	15, 21, 25

Score bands

• 13-15: you are ready to build your own small project from scratch (see "Your next independent project" in Lesson 18).
• 9-12: pass. Reread the lessons linked from the questions you missed, then retake the quiz.
• Below 9: work through the lesson practice tests for Lessons 1 to 18 first, then retake the quiz in a few days.

Related on TechInterviewNotes

• Free mock: Mock Interview: C# Core Language (Mid-Level), a 25-question, 35-minute mock for when you want an interview-style test.
• Mock: Mock Interview: C# and .NET Interview Questions and Answers (Full Access).