const EventEmitter = require('events');

class Person extends EventEmitter {
constructor(name) {
super();
this.name = name;
}
}

let xiaoming = new Person('xiaoming');
let lili = new Person('lili');
let lucy = new Person('lucy');

let person = [xiaoming, lili, lucy];

person.forEach(function(person) {
person.on('speak', function(message) {
console.log(person.name + "say" + message);
})
});

xiaoming.emit('speak', 'hi');