实现继承示例一：
<script language="javascript" type="text/javascript">
function ClassA(sColor)
{
this.color=sColor;
}
ClassA.prototype.sayColor=function()
{
alert(this.color);
}
function ClassB(sColor,sName)
{
ClassA.call(this,sColor);
this.name=sName;
}
ClassB.prototype=new ClassA();
ClassB.prototype.sayName=function()
{
alert(this.name);
}
var objA=new ClassA("red");
var objB=new ClassB("blue","Nicholas");
objA.sayColor();
objB.sayColor();
objB.sayName();
</script>
实现继承示例二：
<script language="javascript" type="text/javascript">
function Polygon(iSides)
{
this.sides=iSides;
}
Polygon.prototype.getArea=function()
{
return 0;
}
function Trangle(iBase,iHeight)
{
Polygon.call(this,3);
this.base=iBase;
this.height=iHeight;
}
Trangle.prototype=new Polygon();
Trangle.prototype.getArea=function()
{
return 0.5*this.base*this.height;
};
function Rectangle(iLength,iWidth)
{
Polygon.call(this,4);
this.length=iLength;
this.width=iWidth;
}
Rectangle.prototype=new Polygon();
Rectangle.prototype.getArea=function()
{
return this.length*this.width;
};
var triangle=new Trangle(12,4);
var rectangle=new Rectangle(2,2);
document.write("三角形的边数：",triangle.sides,"<br />");
document.write("三角形的面积：", triangle.getArea(), "<br />");
document.write("矩形的边数：", rectangle.sides, "<br />");
document.write("矩形的面积：", rectangle.getArea(), "<br />");
</script>