Important C# Topics

IDisposable and Using

Release resources deterministically with using declarations.

Introduction

Managed memory is reclaimed automatically, but files, sockets, and similar resources should be disposed promptly.

The using declaration guarantees Dispose runs at the end of the scope, including when an exception occurs.

Runnable C# example

Program.cs

using System;
using System.IO;

class Program
{
    static void Main()
    {
        using var writer = new StringWriter();
        writer.Write("resource-safe output");
        Console.WriteLine(writer.ToString());
    }
}

Result of running the code

resource-safe output

Practice with the debugger

Set a breakpoint on an important assignment or condition, click Debug, and inspect the local values before stepping to the next line.

Practice with a challenge

Use what this lesson covers to solve a real problem. Each challenge runs in your browser with instant tests and an AI review.

RAII Release Order Work out the order in which scoped resources are released when their scopes end, as RAII guarantees. Medium

All challenges