var EventEmitter = require('events').EventEmitter;

var emitter = new EventEmitter();

console.log(emitter.getMaxListeners());

//设置可监听事件的最大个数

emitter.setMaxListeners(11);

function work(who){

    console.log(who + ' go to work')

}

//监听事件

emitter.on('do', work);

emitter.on('do', function(who) {

    console.log(who + ' wash clothers')

});

emitter.on('rest', function(who) {

    console.log(who + ' can have a rest');

})

//移除监听事件

emitter.removeListener('do', work);

//触发事件

emitter.emit('do', 'John');

emitter.emit('do', 'lily');

emitter.emit('rest', 'Tom');

//所有‘do’的监听事件

console.log(emitter.listeners('do'))

//监听事件的个数

console.log(emitter.listenerCount('do'));