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The length property sets or returns the number of options in a drop-down list.
length属性可设置或返回下拉列表的可选项目的数量
selectObject.length=number |
<html> <head> <script type="text/javascript"> function getLength() { alert(document.getElementById("mySelect").length) } </script> </head> <body> <form> <select id="mySelect"> <option>Apple</option> <option>Pear</option> <option>Banana</option> <option>Orange</option> </select> <input type="button" onclick="getLength()" value="How many options in the list?"> </form> </body> </html> |
Get the number of options in the dropdown list
得到下拉列表可选项目的数量