比如，我们定义了一个Classroom对象，这里我们定一个事件，当教室里的人增加超60人时就触发一个事件onFull;具体定义如下：

复制代码 代码如下:

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);