ES5 自定义方式

function Pub() {
  this.handler = {};
}
Pub.prototype.on = function(type, handle) {
  if (!this.handler[type]) {
    this.handler[type] = [];
  }
  this.handler[type].push(handle);
};

Pub.prototype.emite = function() {
  var type = Array.prototype.shift.apply(arguments);
  if (this.handler[type]) {
    var handles = this.handler[type];
    handles.forEach(element => {
      element.apply(this, arguments);
    });
  }
};

Pub.prototype.off = function(type, handle) {
  if (this.handler[type]) {
    var handles = this.handler[type];
    for (var i = 0; i < handles.length; i++) {
      if (handles[i] == handle) {
        handles.splice(i, 1);
        i--;
      }
    }
  }
};

var p1 = new Pub();
function handle(name) {
  console.log(`this is the input name:${name}`);
}

p1.on("add", handle);
p1.on("add", function() {
  console.log(`这是另一个事件`);
});
p1.off("add", handle);
p1.emite("add", "wangpeng");

###ES6 的 Seter 构造器