Design patterns

Creational Patterns

Singleton

class DbConn {
  private static instance: DbConn | undefined;
  private constructor() {}
  public connect(): void {}
  public disconnect(): void {}
  public static getInstance(): DbConn {
    if (!DbConn.instance) DbConn.instance = new DbConn();
    return DbConn.instance;
  }
}

const dbconn = DbConn.getInstance()

Abstract Factory

Factory Method

Builder

Prototype

Structural Patterns

Adapter

Bridge

Composite

Decorator

Façade

Flyweight

Proxy

Behavioral Patterns

Chain of responsibility

Command

Interpreter

Iterator

Mediator

Memento

Observer

State

Strategy

Template Method

Visitor