The Singleton pattern is often used for cases where a global state or resource needs to be shared across the entire application.
It is common in cases like configuration settings or managing connections to a shared resource (e.g., a database or API).
@Singleton
class Database {
constructor(public host: string, public port: number) {}
}
const db1 = new Database('localhost', 5432);
const db2 = new Database('localhost', 5432);
console.log(db1 === db2); // true, both db1 and db2 refer to the same instance
When applied to a class, it ensures that only a single instance of the class can be created. If an attempt is made to create another instance, the existing instance will be returned.