JavaScript 事件对象的实现_javascript技巧

var Classroom=function()
{
this.numberOfPeople=0;
this.onFull=null;
this.peopleEnter=function(number)
{
this.numberOfPeople+=number;
if(this.numberOfPeople>60&&this.onFull!=null)
{
this.onFull(this.numberOfPeople);
}
}
}
function show1(number)
{
alert("教室里有"+number+"人");
}
function show2(number)
{
alert("教室里超出了"+(number-60)+"人");
}
var classroom1=new Classroom();
classroom1.onFull=show1;
classroom1.peopleEnter(30);
classroom1.peopleEnter(32);
classroom1.onFull=show2;
classroom1.peopleEnter(34);