JSFiddle - React, Tailwind, and code Playground

HTML

<p>Some text for testing this thing. I want to remove the dependency on this div#selection but cannot figure out how to do it!</p>
<div id="selection"></div>

CSS

#element {
    width: 20px;
    height: 20px;
    background-color: #CCC;
    display: inline-block;
}

JavaScript

var my_array1 = [1, 2, 3] 
var my_array2 = [1, 1, 1]


function isUnique(obj)
{
   var unique=obj.filter(function(itm,i,a){
      return i==a.indexOf(itm);
   });   
    return unique.length==obj.length?true:false;
    
}


alert(isUnique(my_array1))
alert(isUnique(my_array2))