运行 ❯
获取您
自己
的网站
×
更改方向
保存代码
更改主题，深色/浅色
前往 Spaces
<!DOCTYPE html> <html> <body> <p>Do not select a fruit, just click the button. The selectedIndex property will return "-1" if no options are selected.</p> <select id="mySelect" size="4"> <option>Apple</option> <option>Orange</option> <option>Pineapple</option> <option>Banana</option> </select> <button type="button" onclick="myFunction()">Display index</button> <script> function myFunction() { var x = document.getElementById("mySelect").selectedIndex; alert(x); } </script> </body> </html>
