JSFiddle - React, Tailwind, and code Playground

by synz izynz

HTML

<table class="list">
   <tr class="8008"><td>8008</td></tr>
   <tr class="8002"><td>8002</td></tr>
   <tr class="8008"><td>8008</td></tr>
   <tr class="8088"><td>8088</td></tr>
   <tr class=""><td></td></tr>
   <tr class="8077"><td>8077</td></tr>
   <tr class="8077"><td>8077</td></tr>
</table>

CSS

.alert{
  background:red;
}

JavaScript

var arr1 = [];
    var arr2 = [];
    $(".list > tr").each(function(){
    		arr1.push($(this).class());
    });
    console.log(arr1.length);
    $(".list > tr").each(function(index){
    		var newArray = arr1.slice();
       	newArray.splice(index, 1); // remove index value from an array, so this index != match its own
 				console.log(newArray);
        if ($.inArray($(this).class(), newArray ) !== -1)
        		$(this).addClass("alert");
        
    });