Every question is hand-checked, every answer comes with an explanation, and your progress builds into a clear picture of where you stand.
Every C# question shows its code before you answer, so you are reading real C#, not a description of it.
Once you attempt a question you get the reasoning, not just a tick. That matters most on C#, where structs versus classes, boxing, async and await state machines, linq deferred execution, idisposable, and nullable reference types.
Progress is tracked per topic across the 49 C# topics, so revision points at the gaps instead of the whole list.
580 C# questions right now: 76 easy, 258 medium and 246 hard. That number is read straight from the question table when this page is built, so it is never a rounded marketing figure.
No. Every C# question, including its code snippet, its difficulty and its topic, is readable without signing in. You need a free account only to submit an answer, see which option is correct, and read the worked explanation. We keep it that way so the platform stays honest about what you actually got right.
Structs versus classes, boxing, async and await state machines, LINQ deferred execution, IDisposable, and nullable reference types.
49 distinct topics are tagged on the C# questions, including events and observer pattern, IEnumerable vs IQueryable, expression trees, Span and Memory, GC generations and LOH, volatile and memory barriers. The topic labels come from the questions themselves, so the list matches what you will actually be asked.
Yes. Reading is free and unlimited. A free account unlocks answering, explanations and progress tracking. Pro (₹199 per month) adds AI explanations and AI-graded guesstimates on top; it is not needed to practise C# MCQs.
Enterprise back ends on .NET, Unity game development, and Windows tooling.
These are 12 of the 580 C# questions in the library, pulled live from the question table. The snippet, the difficulty and the topic are all here. The answer options and the explanation are not. Those need a free account.
Structs versus classes, boxing, async and await state machines, LINQ deferred execution, IDisposable, and nullable reference types.
var d = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
d["Hello"] = 1;
d["HELLO"] = 2;
Console.WriteLine(d.Count + " " + d.Keys.First());IQueryable<Order> q = db.Orders;
var result = q.Where(o => o.Total > 100)
.AsEnumerable()
.Where(o => o.Notes.Contains("urgent"))
.ToList();var items = new List<string> { "a", "b" };
foreach (var item in items)
{
item = item.ToUpper();
}var n = 3.0;var value = null;var nums = new[] { 1, 2, 3, 4 };
var result = nums.Where(n => n % 2 == 0).Select(n => n * 10);
Console.WriteLine(string.Join(",", result));int? x = 5;
Console.WriteLine(x.GetType());struct Point { public int X; }
var a = new Point { X = 5 };
var b = a;
b.X = 99;
Console.WriteLine(a.X);
Console.WriteLine(b.X);double rate = 0.5;
Console.WriteLine($"{rate:P0}");void Print(in int x) => Console.WriteLine(x);int[] arr = { 1, 2, 3 };
int[] copy = arr;
copy[0] = 42;
Console.WriteLine(arr[0]);async Task<int> LoadAsync()
{
var data = await FetchAsync();
return data.Length;
}We keep the correct answer, the explanation and the scoring behind sign-in so the platform stays honest, which is why the correct option and the worked explanation for every C# question stay behind a free account. Signing in is free and takes a few seconds.
Enterprise back ends on .NET, Unity game development, and Windows tooling.