Singleton class

toybz

The Singleton class contains a single instance of the class. This instance is stored in a variable named Singleton.singleton. The Singleton class has a private constructor so that no other instances of the class are created. The public static getInstance() method returns the singleton instance.

export class Singleton {
  // A variable that stores the singleton object. Initially,
  // the variable acts like a placeholder
  private static singleton: Singleton;
  // private constructor so that no instance is created
  private constructor() {
  }
  // This is how we create a singleton object
  public static getInstance(): Singleton {
    // check if an instance of the class is already created
    if (!Singleton.singleton) {
      // If not created create an instance of the class
      // store the instance in the variable
      Singleton.singleton = new Singleton();
    }
    // return the singleton object
    return Singleton.singleton;
  }
}