javascript - 如何遍历具有相同类的 li 标签列表并更改其相应的样式

Question

I have a list of li tags having same class and and i want to change their styles and their children elements styles when ever a user hover over each the li which is the container, below is the code I have tried. I used getElementsByClassName to get the node list of all li tags, now, what I want to do is add event listener to each one of them and manipulate the style of each when ever a user triggers a mouseover event

function doFirst(){
    var playList = document.getElementsByClassName("list");
    var play = document.getElementsByClassName("play");
    var plus = document.getElementsByClassName("plus");
    var title = document.getElementsByClassName("title");

    function songHover (e){
        playList[0].style.backgroundColor = "#ccc";
        play[0].style.display = "block";
        plus[0].style.display = "block";
        title[0].style.width = "50%";
    }
    function songHoverOut (e){
        playList[0].style.backgroundColor = "#fff";
        play[0].style.display = "none";
        plus[0].style.display = "none";
        title[0].style.width = "auto";
    }
    playList[0].addEventListener("mouseover", songHover, false);
    playList[0].addEventListener("mouseleave", songHoverOut, false);

}
window.addEventListener("load", doFirst, false);

content .song-list{
    width: 100%;
    height: auto;
}
content .song-list ul{
    margin-bottom:4%;
    display: flex;
    flex-direction: column;
}
content .song-list ul > p{
    width: 100%;
    padding: 6% 0 1% 0;
    font-size: 140%;
    color: #2b32b2;
}
content .song-list ul li{
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    height: 10%;
    margin-bottom: 6%;
    padding: 2%;
}
.title{
    border: 0px solid red;
    flex:1;
    max-width: 80%;
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-start;
}
.title h4{
    font-weight: normal!important;
    font-size: 98%;
    white-space: nowrap;
    overflow: hidden;
    margin-bottom: 4px;
    width: 100%;
}
.title p{
    font-size: 85%;
    white-space: nowrap;
    overflow: hidden;
    margin-right: 8px;
}
.title p:first-child{
    flex:1;
}
.title p:last-child{
    max-width: 50%;
}
content .song-list ul li i{
    display: none;
    border: 0px solid red;
    width: 15%;
    text-align: center;
    padding: 3.8% 0;
}
.play{

}
.plus{

}
.duration{
    display: block;
    border: 0px solid red;
    margin-left: auto;
    width: 20%;
    text-align: right;
    padding: 3.8% 0;
}

<div class="song-list">
  <ul>
      <p>A</p>
      <li class="list">
          <span class="title">
              <h4>A Sky Full Of Stars</h4>
              <p>Coldplay</p>
              <p>Ghost Stories</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">4:28</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>The A Team (george.ortha@ferialaw.com)</h4>
              <p>Ed Sheeran</p>
              <p>+</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">4:18</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Adore You</h4>
              <p>miley Cyrus</p>
              <p>bangerz</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">4:38</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Adorn (george.ortha@ferialaw.com)</h4>
              <p>Miguel</p>
              <p>Kaleidoscope Dream</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">3:13</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Again</h4>
              <p>Fetty Wrap</p>
              <p>Billboard Hot 100 Singles Chart</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">5:12</span>
      </li>
  </ul>
  <ul>
      <p>B</p>
      <li class="list">
          <span class="title">
              <h4>
              Back to December (george.ortha@ferialaw.com)
              </h4>
              <p>Tailor Swift</p>
              <p>2011 Billboard Chart</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">4:43</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Bad (george.ortha@ferialaw.com)</h4>
              <p>Wale</p>
              <p>The Gifted</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">4:14</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Bad Blood</h4>
              <p>Tailor Swift</p>
              <p>2011 Billboard Chart</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">5:12</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Bartender</h4>
              <p>Lady Antebellum</p>
              <p>747</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">5:12</span>
      </li>
      <li class="list">
          <span class="title">
              <h4>Believe Me</h4>
              <p>Lil Wayne</p>
              <p>Believe Me</p>
          </span>
          <i class="play">></i>
          <i class="plus">+</i>
          <span class="duration">5:12</span>
      </li>
  </ul>
</div>
    

Answer 1

我认为更简单的解决方案是 css :hover 伪类(当用户将光标悬停在元素上时更改样式)。

示例:.parent:hover .some-child {hover styles}。