Home
HTML
HTML
Tryit: HTML
运行 ❯
×
Change Orientation
Change Theme, Dark/Light
<!DOCTYPE html> <html> <head> <style> input:required { background-color: yellow; } </style> </head> <body> <h3>:required 选择器的演示。</h3> <p>一个可选的输入元素：<br><input></p> <p>一个必需的输入元素：<br><input required></p> <p>:required 选择器选择带有"required"属性的表单元素。</p> <p>Internet Explorer 9 或更早版本不支持 :required 选择器。</p> </body> </html>