C# online IDE & code editor for technical interviews

Guidelines to use C# in this online IDE

Our C# environment runs on Microsoft’s cross-platform .NET Core runtime. The System.Json assembly is linked.

You should define a static void Main on a class named Solution.

Tests can be written in NUnit. Note that if you run NUnit tests, you should only use the test runner’s main method, like so:

using NUnit.Framework;
using NUnitLite;
using System;
using System.Reflection;

public class Runner {
    public static int Main(string[] args) {
        return new AutoRun(Assembly.GetCallingAssembly()).Execute(new String[] {"--labels=All"});
    }

    [TestFixture]
    public class Dog {
        public String bark() {
            return "bark";
        }

        [Test]
        public void TestBarker() {
            Assert.AreEqual("bark", new Dog().bark());
        }
    }
}
Code language: C# (cs)

You should be able to run LINQ queries, like so:

using System;
using System.Linq;

class Solution
{
    static void Main(string[] args)
    {
        int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

        var lowNums =
            from n in numbers
            where n < 5
            select n;

        Console.WriteLine("Numbers < 5:");
        foreach (var x in lowNums)
        {
            Console.WriteLine(x);
        }
    }
}
Code language: C# (cs)

Your code is compiled and run with debug mode enabled.