构造函数+原型混合方式实现js的继承

function ClassA(sColor){
this.color = sColor;
}

ClassA.prototype.sayColor = function(){
console.log(this.color);
}

function ClassB(sColor, sName){
ClassA.call(this, sColor);
this.Name = sName;
}

ClassB.prototype = new ClassA();

ClassB.prototype.sayName = function(){
console.log("name is " + this.Name);
}

var ca = new ClassA("red");

ca.sayColor();

var cb = new ClassB("blue","george");

cb.sayColor();
cb.sayName();