JavaScript 学习笔记 一 动态性

//动态性是指，在一个 Javascript 对象中，要为一个属性赋值，我们不必事先创建一个字段，//只需要在使用的时候做赋值操作即可var obj = new Object();obj.name = "aa  ";obj.sayHi = function(){return "Hi "+obj.name;}function say(){alert(obj.sayHi());}var objarr = new Array("cc", "aa");var objstr = new String("hello");// 类型的判function handle(msg){     alert(msg);    say();}function handleMsg(msg,handle){    if(handle instanceof Function)        handle(msg);    else        throw new Error("the 2nd argument should be a function");}handleMsg("hello aa",handle);handleMsg("hello aa"," cc");