Question

我正在尝试制作货币转换器，但querySelector为空，我不知道如何解决。

HTML：

<html>
    <head>
        <meta charset="utf-8">
        <script type="text/javascript" src="valuta.js"></script>
        <link rel="stylesheet" type="text/css" href="valuta.css">
    </head>
    <body>
        <div class="ddk">
            <input type="number" placeholder="DDK">
        </div>  

        <div id="usd">
            <input type="number" placeholder="DDK">
        </div>  

        <div id="eur">
            <input type="number" placeholder="DDK">
        </div>

    </body>
</html>

JS：

const ddk = document.querySelector('#ddk > input');
const usd = document.querySelector('#usd > input');
const eur = document.querySelector('#eur > input');

console.log(ddk);

Answer 1

const ddk = document.querySelector('.ddk > input');

#匹配ID，.匹配类别。

const ddk = document.querySelector('.ddk > input');
console.log(ddk);

<html>
    <head>
        <meta charset="utf-8">
        <script type="text/javascript" src="valuta.js"></script>
        <link rel="stylesheet" type="text/css" href="valuta.css">
    </head>
    <body>
        <div class="ddk">
            <input type="number" placeholder="DDK">
        </div>  

        <div id="usd">
            <input type="number" placeholder="DDK">
        </div>  

        <div id="eur">
            <input type="number" placeholder="DDK">
        </div>

    </body>
</html>

const ddk = document.querySelector（'＃ddk> input'）;不起作用？只是在控制台中显示null

1 个答案: