Как написать скрипт на JS?

function slideShow(){ 
    var $next = $(".slide.active").next(".slide"); 
    $(".slide.active").removeClass('active'); 
    if(!$next.length) $next = $(".slide").eq(0); 
     
    $next.addClass('active'); 
} 
 
 
setInterval(slideShow, 3000);

.slide { 
   display: none; 
   color: red; 
} 
 
.slide.active { 
  display: block; 
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
<div class='wrapper'> 
   <div class='slide active'>slide-1</div> 
   <div class='slide'>slide-2</div> 
   <div class='slide'>slide-3</div> 
   <div class='slide'>slide-4</div> 
   <div class='slide'>slide-5</div> 
</div>