我正在尝试以下代码并得到以下结果:
console.log(document.getElementsByTagName('a')[0]); //retuns <a id="link" href="http://stackoverflow.com/questions/ask"></a>
console.log($('a')[0]);//retuns <a id="link" href="http://stackoverflow.com/questions/ask"></a>
console.log(document.getElementById('link'));//retuns <a id="link" href="http://stackoverflow.com/questions/ask"></a>
console.log(document.getElementById('link')[0]);// returns undefined
console.log($('#link')[0]); //retuns <a id="link" href="http://stackoverflow.com/questions/ask"></a>
谁能说出为什么这些 (console.log(document.getElementById('link')[0]);// returns undefined
和console.log($('#link')[0]); //retuns <a id="link" href="http://stackoverflow.com/questions/ask"></a>
) 行为怪异?