以下是題目，需要補(bǔ)充代碼。自認(rèn)不才，特來(lái)求助各位大神，望指點(diǎn)迷津.題目是讓補(bǔ)全 A 的代碼，讓這個(gè)代碼可以跑起來(lái)，輸出對(duì)應(yīng)的結(jié)果var A = function () {    this.name = 'apple';}A.prototype.getName = function () {    return this.name;}//補(bǔ)充代碼var B = A.extend({    initialize: function () {        this.superclass.initialize.call(this);        this.total = 3;    },    say: function () {        return '我有' + this.total + '個(gè)' + this.getName()    }});    var b = new B();    console.log(b.say());//我有3個(gè)apple;