如何通过 JavaScript 获取 HTML 元素值？

Question

<div class="gallery_re_form">
  <form action="http://gall.dcinside.com/?/forms/comment_submit" method="post" accept-charset="utf-8" name="comment_write" id="comment_write" />
      <div style="display:none">
          <input type="hidden" name="ci_t" value="625752bb366f010c56e506e5d0f93822" />
      </div>
      <input type="hidden" name="ehqo_C" id="ehqo_C" value="spam_key" />
      <input type="hidden" name="spam_key" id="spam_key" value="rhkdrhgkwlak!!" />
      <input type="hidden" name="fb8f95190d2b70480acb309f91653d7e4416d4f99a0b67a0b866f06087fdec4588f68fe210675e74919d2ecc50e08f1fd6f75119" id="fb8f95190d2b70480acb309f91653d7e4416d4f99a0b67a0b866f06087fdec4588f68fe210675e74919d2ecc50e08f1fd6f75119" value="b9d3cc45576e30144d8f299fdc61356552989b3aba08238c811b1d3183a104cc2d1d3984af72c4f2eaa2738ca41819d05533731a" />
      <input type="hidden" name="service_code" value="21ac6e96ad152e8f15a05b7350a24759b5606fa191c17e042e4d0175735f4c61d63153c3ce7b4eb89b565a7f6a04ad0667df75f39625ab6fe0816d23f4bed5387546b52d6874b5c201e54df7b5db9187219b048cffc9ef8a106febabfba125eff122df732d9cc52fcaae8b11c42ff5f6fd5ef81901df4103827e7233615992141c180be76852634d53b60c6f911ccdfc762b3db554d8ee36528547bceede30697120c5291acb255a" />
      <br />
      <div class="re_input">
          <div>
              <ul>
                  <li>
                      <input type="text" name="name" id="name" class="re_name re_in" onfocus="this.style.background='#FFFFFF'" title="nickname" />
                  </li>
                  <li>
                      <input type="password" name="password" id="password" class="re_pw re_in" onfocus="this.style.background='#FFFFFF'" title="password" />
                  </li>
              </ul>
          </div>
      </div>
  </form>

我正在尝试重写 google chrome 扩展。我想在此 HTML 响应中获取#spam_keys#service_code值。

我没有使用过 JavaScript。

如何通过 JavaScript 获取 HTML 元素 id（spam_key、service_code）和值？

Answer 1

DOM有一个document对象，你可以像这样使用它来获取你想要的HTML元素

document.getElementById("id")

现在要获取值，只需使用value该元素的属性即可。

document.getElementById("id").value