<!DOCTYPE html><html><head> <title></title> <style type="text/css"> .show{ width: 100px; height: 100px; border: 1px solid pink; } </style> <script type="text/javascript"> function rec(){ var gg=document.getElementsByClassName("close"); gg.className="show"; } </script></head><body><div class="close">hello world</div><input type="button" name="" value="change" onclick="rec()"></body></html>
为什么这样没效果?
要把class="close"改成id="close";通过var gg=document.getElementById("close");才有效?
当年话下