​x
 
<html>
<head>
<title>Example</title>
</head>
<body>
<script type="text/javascript">
function ClassA(sColor) {
    this.color = sColor;
    this.sayColor = function () {
        alert(this.color);
    };
}
​
function ClassB(sColor, sName) {
    //this.newMethod = ClassA;
    //this.newMethod(color);
    //delete this.newMethod;
    ClassA.apply(this, arguments);
​
    this.name = sName;
    this.sayName = function () {
        alert(this.name);
    };
}
​
var objA = new ClassA("blue");
var objB = new ClassB("red", "John");
objA.sayColor();
objB.sayColor();
objB.sayName();
​
</script>
 
</body>
</html>
​