How to define Singleton in TypeScript

Question

What is the best and most convenient way to implement a Singleton pattern for a class in TypeScript? (Both with and without lazy initialisation).

Answer 1

Add the following 6 lines to any class to make it "Singleton".

class MySingleton
{
    private constructor(){ /* ... */}
    private static _instance: MySingleton;
    public static getInstance(): MySingleton
    {
        return this._instance || (this._instance = new this());
    };
}

Test example:

var test = MySingleton.getInstance(); // will create the first instance
var test2 = MySingleton.getInstance(); // will return the first instance
alert(test === test2); // true

[Edit]: Use Alex answer if you prefer to get the instance through a property rather a method.