将鼠标悬停在链接上时更改div的背景图像

Question

I have a navigation menu and i'd like the background image of an adjacent div to change to a different image when i hover over each of the menu links . I've tried using jquery to add the class of side-menu1 which has a different background image . this would then need to be replicated for each of the 5 links

$(document).ready(function() {
  $('.evo').hover(function() {
    $('.side-menu').addClass('.side-menu1');
  }, function() {
    $('.side-menu').removeClass('.side-menu1');
  });
});

nav {
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  width: 100%;
  text-align: left;
  box-sizing: border-box;
  z-index: 10001;
  left: -100%;
}

nav ul {
  width: 50%;
  float: left;
  list-style-type: none;
  padding: 0;
  height: 100%;
  margin: 0;
}

nav ul li {
  width: 100%;
  height: 20%;
  box-sizing: border-box;
  padding-top: 9vh;
  background: rgba(0, 0, 0, 1);
  transition: all 1s;
  position: relative;
  padding-left: 80px;
}

nav ul li a {
  font-family: 'battle';
  color: white;
  font-size: 14px;
  letter-spacing: 14px;
  text-decoration: none;
}

nav ul li:hover {
  background: rgba(0, 0, 0, 0.95);
}

.underline {
  position: absolute;
  bottom: 60px;
  left: 0;
  height: 1px;
  background: rgba(38, 157, 171, 0.8);
  width: 0%;
  transition: all 1s ease-in-out;
  display: block;
  z-index: 10001;
  margin-left: 80px;
}

nav ul li:hover .underline {
  width: 260px;
}

.side-menu {
  height: 100%;
  width: 50%;
  float: left;
  background-image: url(../img/menu-donut.png);
  transition: all 1s ease-in-out;
}

.side-menu1 {
  background-image: url(../img/menu-hci.png);
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<nav class="slideout-menu">
  <ul>
    <li>
      <a href="#">POTOCKI</a><span class="underline"></span>
    </li>
    <li class="evo">
      <a href="#">EVOLUTION</a><span class="underline"></span> 
    </li>
    <li>
      <a href="#">COLOUR IDEAS</a><span class="underline"></span>
    </li>
    <li>
      <a href="#">FAT DONUT</a><span class="underline"></span>
    </li>
    <li>
      <a href="#">SEAN CARVER</a><span class="underline"></span>
    </li>
  </ul>
  <div class="side-menu"></div>
</nav>

Answer 1

Be careful about addClass() function. The dot is not valid here.

Should be this :

$(document).ready(function() {
  $('.evo').hover(function() {
    $('.side-menu').addClass('side-menu1');
  }, function() {
    $('.side-menu').removeClass('side-menu1');
  });
});

Working example