简单的为按钮添加点击事件

简单的为按钮添加点击事件

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title></title>

</head>

<body>
    <button id="btn">点击</button>
    <div id="demo" style="display: none;">这是一个惊喜！</div>
    <script>
        function show() {
            let oBtn = document.getElementById("btn");
            let oDemo = document.getElementById("demo");
            oBtn.onclick = function() {
                oDemo.style.display = 'block';
            }
        }
        show('btn', 'demo');
    </script>
</body>

</html>