JSFiddle - React, Tailwind, and code Playground

HTML

<body class="foo-123">
<a href="#" class="bar-456">Item 456</a>
<a href="#" class="bar-789">Item 789</a>
<a href="#" class="bar-123">Item 123</a>

</body>

CSS

.bodySharesClass {
  color:red;
}

JavaScript

$('[class^=bar]').each(function(i,v){
   var numb = $(this).attr('class').split('-')[1];
  if ($('body').is('.foo-'+numb)) {
   $(this).addClass('bodySharesClass');
   }
})