Singleton

Service Lifetimes: Singleton, Scoped, Transient

How ASP.NET Core's built-in dependency injection container manages object lifetime through Singleton, Scoped, and Transient registrations.

Singleton Pattern

Ensures a class has only one instance and provides a single global point of access to it.

Singleton and Factory Patterns

Learn how Singleton guarantees a single instance and how Factory Method delegates object creation to a central point.

Java Design Patterns Cheat Sheet

Shows implementations of core Gang of Four design patterns including Singleton, Factory Method, Builder, and Observer in Java.

What is the Singleton Pattern?

The Singleton pattern restricts a class to exactly one instance and provides a single global access point to that instance, typically via a static method.

What is a Companion Object?

A companion object is a singleton tied to a specific class (in languages like Kotlin and Scala) that holds members logically scoped to the class itself rather…

What is a Companion Object in Kotlin?

A companion object in Kotlin is a single, compiler-generated singleton declared inside a class with the `companion object` keyword that holds members callable…