1。私有实现：
实现原则：
·私有属性可以在构造函数中使用var关键字定义
·私有属性只能由特权函数（privileged function）公用访问。特权函数：使用this定义的函数
示例：
function
Vehicle()
...
{ var wheelCount = 4; //私有属性 this.getWheelCount = function()...{ // 特权函数
return wheelCount; } this.setWheelCount = function(count)...{ wheelCount = count; } }
var
vehicle
=
new
Vehicle();vehicle.setWheelCount(
5
);
var
wheel
=
vehicle.getWheelCount();alert(wheel);
2。继承实现
通过脚本实现。 如
function
Vehicle()
...
{ var wheelCount = 4; this.getWheelCount = function()...{ return wheelCount; } this.setWheelCount = function(count)...{ wheelCount = count; } }
/**/
/* 实现继承 */
function
createInheritance(parent,child)
...
{ var property; for(property in parent)...{ if(!child[property]) child[property] = parent[property]; }}
function
Child()
...
{ }
var
child
=
new
Child();createInheritance(
new
Vehicle(),child);alert(child);
3。参考文献：
《 Ajax.基础教程》第5章
