prototype

Shape = Class.create(); 
Shape.prototype = { 
    initialize:function(color){ 
        this.color = color; 
        //alert('in initialize'); 
    },
    draw:function(){ 
        alert("in draw"); 
        alert(this.color); 
    }
}

Circle = Class.create(); 
Circle.prototype = Object.extend(new Shape(),{ 
    initialize:function(color,radius){ 
        //alert('in Circle initialize'); 
        this.color = color; 
        this.radius = radius; 
    }, 
    drawCircle:function(){ 
        alert("in drawCircle"); 
        alert("color:"+this.color); 
        alert("radius:"+this.radius); 
    } 
})

var circle = new Circle("green", 10);
alert(circle instanceof Shape);
alert(circle instanceof Circle);

var shape = new Shape("red");
alert(shape instanceof Shape);
alert(shape instanceof Circle);

 

function class1(){
}

class1.prototype = {
    m1 : function() {
        alert(1);
    }
}

function class2(){
}

class2.prototype = class1.prototype;
class2.prototype.method = function(){
    alert(2);
}

var obj1 = new class1();
var obj2 = new class2();

obj1.method();
obj2.method();

obj1.m1();
obj2.m1();

class2.prototype.m1 = function() {
    alert(3);
}

obj1.m1();
obj2.m1();