public final class Singleton {
private static final Singleton INSTANCE = new Singleton();
private Singleton() {}
public static Singleton getInstance() {
return INSTANCE;
}
}let instance;
let counter = 0;
class Counter {
constructor() {
if (instance) {
throw new Error("You can only create one instance!");
}
instance = this;
}
}
const singletonCounter = Object.freeze(new Counter());
export default singletonCounter;class Singleton(object):
__instance = None
def __new__(cls, *args):
if cls.__instance is None:
cls.__instance = object.__new__(cls, *args)
return cls.__instance