<html><head> <meta charset="UTF-8"> <script type="text/javascript" > var x=document.getElementsByClassName("btn").length; document.write(x); </script></head><body> <div class="btn">1</div> <div class="btn">2</div> <div class="btn">3</div> <div class="btn">4</div></body></html>為何輸出結(jié)果是01234？
getElementsByClassName("btn").length的輸出
尚方寶劍之說(shuō)
2019-03-12 15:19:51
