Home
JS
JS
Tryit: JAVASCRIPT
运行 ❯
×
Change Orientation
Change Theme, Dark/Light
<!DOCTYPE html> <html> <head> <style> .democlass { color: red; } </style> </head> <body> <h1>Hello World</h1> <p>单击按钮将 H1 的类属性设置为“democlass”。</p> <button onclick="myFunction()">试一试</button> <script> function myFunction() { var h = document.getElementsByTagName("H1")[0]; var typ = document.createAttribute("class"); typ.value = "democlass"; h.attributes.setNamedItem(typ); } </script> </body> </html>