对象之成员函数：
对象不仅只有属性，还要有行为（函数）
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script language="JavaScript" type="text/javascript">
function Person(name, age) {
//传递实参初始化属性
this.name = name;
this.age = age;
// 这就是一个公开的函数，这样的话浪费资源
this.show = function() {
document.write("名字=" + this.name + " " + "年龄=" + this.age + "<br/>");
}
this.add = function() {
var res = 0;
for(var i = 1; i <= 1000; i++) {
res += i;
}
return res;
}
}
var p1 = new Person("宋江", 90);
p1.show();
var p2 = new Person("李逵", 78);
p2.show();
document.write("res=" + p1.add());
</script>
</head>
<body>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script language="JavaScript" type="text/javascript">
function Person(name, age) {
//传递实参初始化属性
this.name = name;
this.age = age;
// 这就是一个公开的函数，这样的话浪费资源
this.add = function() {
var res = 0;
for(var i = 1; i <= 1000; i++) {
res += i;
}
return res;
}
}
function show(){
document.write("名字=" + this.name + " " + "年龄=" + this.age + "<br/>");
}
var p1 = new Person("宋江", 90);
//函数功能传递
p1.abc=show;
p1.abc();
//调用二
p1.bcd=function show1(){
document.write("名字"+this.name);
}
p1.bcd();
</script>
</head>
<body>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script language="JavaScript" type="text/javascript">
function Person(){
this.name="abc";
this.age=900;
this.abc=function(v1,v2){
document.write(this.name+" "+this.age+" "+v1+" "+v2+"<br/>");
}
}
var p1=new Person();
p1.abc();
p1.abc("背景","天津");
var p2=new Person();
p2.abc();
p2.abc("南京","东京");
</script>
</head>
<body>
</body>
</html>
使用prototype去绑定一个函数给shout，直接绑定给类，不需要创建对象时创建新的函数属性
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script language="JavaScript" type="text/javascript">
function dog() {}
var dog1 = new dog();
dog.prototype.shout = function() {
document.write("小狗" + "<br/>");
}
dog1.shout();
var dog2 = new dog();
dog2.shout();
//判定是否为同一个函数
document.write(dog1.shout == dog2.shout);
</script>
</head>
<body>
</body>
</html>
通过==符号可以判断地址是否相等
原文：https://www.cnblogs.com/helloworld2019/p/10930137.html