夺命雷公狗---javascript NO:24 对象之间的赋值操作

1、把对象做为参数进行传递

例1：函数形参值的改变不会影响实参，但是对象除外

1）普通传值

 

<!DOCTYPE html>
<html>
<head>
<meta charset=’utf-8′>
<title></title>
</head>
<body>
<script>
function display(name){
name = ‘lisi';
}
var name = ‘zhangsan';
display(name);
alert(name);  //输出zhangsan
</script>
</body>
</html>

 

 

2）引用传值（object）

 

<!DOCTYPE html>
<html>
<head>
<meta charset=’utf-8′>
<title></title>
</head>
<body>
<script>
function display(obj){
alert(obj.name+’-‘+obj.age);
obj.name = ‘zhangsan';
}
//定义一个自定义类
function Person(){}
var p1 = new Person();
p1.name = ‘lisi';
p1.age = 22;
display(p1);  //lisi-22
alert(p1.name);  //zhangsan
</script>
</body>
</html>

 

 

2、把一个对象做为函数的返回值，返回更多的数据

 

<!DOCTYPE html>
<html>
<head>
<meta charset=’utf-8′>
<title></title>
</head>
<body>
<script>
function display(name,age){
var obj = new Object();
obj.name = ‘zhangsan';
obj.age = 22;
obj.address = ‘广东省广州市';
return obj;
}
var p1 = display();
alert(p1.name+p1.age+p1.address);
</script>
</body>
</html>

 

 

3、实际应用:返回两个数的四则运算

示例：

 

<!DOCTYPE html>
<html>
<head>
<meta charset=’utf-8′>
<title></title>
</head>
<body>
<script>
function display(yi,er){
//定义一个对象
var counter = new Object();
counter.jia = yi + er;
counter.jian = yi – er;
counter.cheng = yi * er;
counter.chu = yi / er;
return counter;
}
var obj = display(100,20);
alert(obj.jia+’—‘+obj.jian+’—‘+obj.cheng+’—‘+obj.chu);
</script>
</body>
</html>

 

posted @ 2015-12-09 10:10  夺命雷公狗  阅读(140)  评论(0)  编辑  收藏  举报