JSFiddle - React, Tailwind, and code Playground

HTML

<div class="slider">
  <ul>
    <li>
      <img src="http://keenthemes.com/preview/metronic/theme/assets/global/plugins/jcrop/demos/demo_files/image1.jpg" alt="" class="active">
    </li>
    <li>
      <img src="https://www.w3schools.com/css/img_lights.jpg" alt="">
    </li>      
    <li>
      <img src="http://keenthemes.com/preview/metronic/theme/assets/global/plugins/jcrop/demos/demo_files/image2.jpg" alt="">
    </li>
    <li>
      <img src="http://images.all-free-download.com/images/graphiclarge/a_london_cityscape_515129.jpg" alt="">
    </li>
    <li>
      <img src="https://image.jimcdn.com/app/cms/image/transf/dimension=1920x400:format=jpg/path/s86d6d6c688ca86fa/image/ie4265a3cd27b2997/version/1451246087/image.jpg" alt="">
    </li>
  </ul>
</div>

<div class="back">Back</div>
<div class="next">Next</div>

CSS

.slider {
    overflow-x: hidden;    
    height: 400px;
    width: 100%;
}
.slider ul {
  width: 500%;
}
.slider ul li {
  float: left;
  list-style: none;
  position: relative;  
  transition: all 0.65s;
}
.next, .back {
  width: 100px; 
  padding: 5px;
  text-align: center;
  background-color: skyblue;
  float: left;
  margin: 10px;
  cursor: pointer;
}

JavaScript

var i = 0;
$('.next').on('click', function() {			
  if (i < 4) {  	
		$('li').animate({'left': '-=600px'}, 300);  
    i++;
  }
  console.log($('li:first').position().left);
  console.log(i);
});

$('.back').on('click', function() {
	if ($('li:first').position().left < 0) {  	
		$('li').animate({'left': '+=600px'}, 300);
    i--;
  }
  console.log(i);
});