C#

Quick Reference Table Feature Abstract Class Interface When to Use Inheritance Single only Multiple allowed Abstract: shared logic; Interface: contracts Implementation Can provide Contract only Abstract: code reuse; Interface: flexibility Constructors Supported Not allowed Abstract: initialization; Interface: pure contracts State/Fields Yes No Abstract: data sharing; Interface: behavior only Performance Slightly faster Virtual dispatch Abstract: hot paths; Interface: most scenarios Testing Can be difficult Easy with mocks Abstract: integration tests; Interface: unit tests Common Pitfalls: ...

Ever used the params keyword in C#? If you write C# code regularly, you probably reach for it whenever you need to pass a variable number of arguments to a method. It’s super handy, letting you skip the tedious step of creating arrays first. But until now, there’s been a limitation: params only worked with arrays. This meant every call created memory allocations with potential performance costs. The good news? C# 14 is changing the game by extending params to work with modern collections like IEnumerable<T>, Span<T>, and more. ...

TL;DR: Immutable objects can’t be changed after creation. In C#, this can make your code safer, easier to test, and bug-resistant, especially in multithreaded or async scenarios. Have you ever had a bug where some object mysteriously changed its value? Or spent hours debugging a weird race condition? Immutability might be the solution you need. In simple terms, immutable objects can’t be changed after they’re created. Instead of modifying an existing object, you create a new one with the updated values. It’s like the difference between editing a document and making a new copy with your changes. ...

Constructor chaining in C# reduces code duplication by allowing one constructor to call another. Learn how to use this technique effectively with examples, best practices, and when to avoid it.

TL;DR: A deadlock happens when threads block each other, waiting for resources that never become available. Most deadlocks in C# are caused by inconsistent lock ordering or mixing sync and async code. Recognize deadlocks by symptoms like app hangs, high thread count, or timeout exceptions. Prevent deadlocks by always acquiring locks in a consistent order, minimizing lock duration, and using lock timeouts. Prefer higher-level synchronization tools like SemaphoreSlim or concurrent collections to reduce risk. In async code, avoid blocking calls like .Wait() or .Result - use await all the way. Use debugging tools and thread dumps to detect and analyze deadlocks in production. Design your multithreaded code with prevention in mind; fixing deadlocks after deployment is much harder. A deadlock is one of the hardest bugs to solve in a multithreaded C# application. It doesn’t cause a crash or an obvious exception; it just brings your application to a silent, grinding halt. If you’ve ever seen a service become completely unresponsive under load for no apparent reason, a deadlock might be the culprit. ...