javascript原型模式发展历程

function Person(name,age){
            var o = new Object();
            o.name=name;
            o.age=age;
            o.sayName=function(){
                alert(o.name)
            }
            return o
        }

        var o1=Person(‘lele‘,5)
        
        var o2=Person(‘mama‘,31)

function Person(name,age){
            this.name=name;
            this.age=age;
            this.sayName=function(){
                alert(this.name)
            }
        }

        var o3=new Person(‘lele‘,5)
        console.log(o3)
        console.log(o3.constructor==Person)
        var o4=new Person(‘mama‘,31)
        console.log(o3.sayName==o4.sayName)

function A(){}
        A.prototype.name=‘lele‘
        A.prototype.age=5
        A.prototype.sayName=function(){
            alert(this.name)
        }
        var o5 = new A();
        var o6 = new A();
        console.log(o5.sayName==o6.sayName)

 function B(name,age){
            this.name=name;
            this.age=age;
        }
        B.prototype.sayName=function(){
            alert(this.anme)
        }

        var o7=new B(‘lele‘,5)

function C(name,age){
            this.name=name;
            this.age=age;
            if(typeof this.sayName != ‘function‘){
                C.prototype.sayName=function(){
                    alert(this.name)
                }
            }
        }
        var o8=new C(‘lele‘,6)