如下代码，什么情况下typeof Constructor.prototype ===

Question

function A( name ){    this.name = name;} function ObjectFactory(){    //console.log(arguments);    var obj = {},    Constructor = Array.prototype.shift.call( arguments );    //console.log(typeof Constructor.prototype);        obj.__proto__ =  typeof Constructor.prototype === 'number'  ? Object.prototype : Constructor.prototype;        var ret = Constructor.apply( obj, arguments );    //console.log(typeof ret);        return typeof ret === 'object' ? ret : obj;    } var a = ObjectFactory( A, 'svenzeng' );