function?DetectorBase()?{
????throw?new?Error('Abstract?class?can?not?be?invoked?directly!');
}

DetectorBase.detect?=?function()?{
????console.log('Detection?starting...');
}
DetectorBase.stop?=?function()?{
????console.log('Detection?stopped.');
};
DetectorBase.init?=?function()?{
????throw?new?Error('Error');
}

//var?d?=?new?DetectorBase();//?Uncaught?Error:?Abstract?class?can?not?be?invoked?directly!

function?LinkDetector()?{}
LinkDetector.prototype?=?Object.create(DetectorBase.prototype);
LinkDetector.prototype.constructor?=?LinkDetector;

var?l?=?new?LinkDetector();
console.log(l);?//LinkDetector?{}__proto__:?LinkDetector
l.detect();?//Uncaught?TypeError:?l.detect?is?not?a?function
l.init();?//Uncaught?TypeError:?l.init?is?not?a?function

主要是倒數(shù)第二行代碼。為什么會(huì)報(bào)錯(cuò)，這里不是應(yīng)該執(zhí)行的嗎？控制臺(tái)應(yīng)該輸出?Detection starting... 嗎？

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我把老師的代碼補(bǔ)全，實(shí)例化，調(diào)用了一下，為什么沒有成功呢？