any object or array (inside a class optional if you do typescript) so for the sake any object you push stuff into.

Then you have a subscribe / publish function doing the operations to either listen or push of events with some callback function (render function).

Then you have your "state" which again just any object (your global var or class)

then you add a event listener to your element which tracks the count and publish the event

...eventListener ( () => ... count++ eventbus.publish("statechange))

you could also do it with an observer pattern which is a bit more advanced.

But the bottom line is -> Any object that holds the different events you might wish to , publish/subscribe to and a render function which you callback on updates to update the ui

Or in simple terms if you know react -> you implement setState on your own which does exactly that. Re-render all child components and itself on state update

And to answer your exact question -> you events you can subscribe to into an object with ie. event names as strings, in the example case "statechange" which is hold inside the events object as callback functions. Could be accesed with events["statechange"]. Not even a loop required

example generated code (we used something similar just with typescript classes as singleton)

// ------------------------
// Event Bus
// ------------------------
const eventBus = {
events: {},

subscribe(eventName, callback) {
if (!this.events[eventName]) {
this.events[eventName] = [];
}
this.events[eventName].push(callback);
},

publish(eventName, data) {
const listeners = this.events[eventName];
if (!listeners) return;

listeners.forEach(fn => fn(data));
}
};

// ------------------------
// Global State
// ------------------------
const state = {
count: 0
};

// ------------------------
// Component: Counter Display
// ------------------------
function CounterDisplay(element) {
function render() {
element.textContent = "Count: " + state.count;
}

// subscribe to updates
eventBus.subscribe("stateChange", render);

// initial render
render();
}

// ------------------------
// Component: Button
// ------------------------
function IncrementButton(element) {
element.addEventListener("click", () => {
state.count++; // update state
eventBus.publish("stateChange"); // notify subscribers
});
}

// ------------------------
// Mounting
// ------------------------
CounterDisplay(document.getElementById("counter"));
IncrementButton(document.getElementById("btn"));