//定义Circle类，拥有成员变量r，常量PI和计算面积的成员函数area()
- function Circle(r) {
- this.r = r;
- }
- Circle.PI = 3.14159;
- Circle.prototype.area = function() {
- return Circle.PI * this.r * this.r;
- }
-
- var c = new Circle(1.0);
- alert(c.area());
- var Circle = function() {
- var obj = new Object();
- obj.PI = 3.14159;
-
- obj.area = function( r ) {
- return this.PI * r * r;
- }
- return obj;
- }
-
- var c = new Circle();
- alert( c.area( 1.0 ) );
- var Circle = new Object();
- Circle.PI = 3.14159;
- Circle.Area = function( r ) {
- return this.PI * r * r;
- }
-
- alert( Circle.Area( 1.0 ) );
- var Circle={
- "PI":3.14159,
- "area":function(r){
- return this.PI * r * r;
- }
- };
- alert( Circle.area(1.0) );
- var Circle = new Function("this.PI = 3.14159;this.area = function( r ) {return r*r*this.PI;}");
-
- alert( (new Circle()).area(1.0) );
js面向对象的五种写法
原文：http://www.cnblogs.com/Shirley-He/p/5062001.html
