exemple4.js

const EventEmitter = require('events');
const myEmitter = new EventEmitter();

let value = 1;
myEmitter.on('event', () => {
    setImmediate(() => {
        value = 2
    });
});
myEmitter.on('event', () => {
    setImmediate(() => {
        value += 2
    });
});
myEmitter.emit('event');
console.log(value); // This will print 1.

setImmediate(() => {
    console.log(value); // This will print 4
});