node.js EventEmitter

event.js

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

function f(){
    // event.call(this);
}
// util.inherits(f, event);
f.prototype = new event();

var ff = new f();

ff.on('do', function(str){
    console.log('1 :' + str);
});

ff.once('do', function(str){
    console.log('2 :' + str);
});

[1,2,3].forEach(function(v, i){
    ff.emit('do', v);
});

//console
1 :1
2 :1
1 :2
1 :3
[Finished in 0.2s]