JSFiddle - React, Tailwind, and code Playground

HTML

<p>
EEWFGWEFGWEGWEGQWG WEFQFQWEF
</p>
<p>
EEWFGWEFGWEGWEGQWG wEFQFQWEF
</p>
<p>
www
</p>
<p>

</p>
<p>
&nbsp;
</p>
<p>
EEWFGWEFGWEGWEGQWG WEFQFQWEF
</p>
<p>
EEWFGWEFGWEGWEGQWG WEFQ11122312FQWEF
</p>

CSS

.bold{color:red;}

JavaScript

function isUpperCase(str) {
    return str === str.toUpperCase();
}

$(function(){
  var arrP = $('p'); //get all p-elements
  if(arrP.length > 0){ //check if there are some p-elements
     for(var i=0; i<arrP.length; i++){ 
		 		var p = $(arrP[i]);
     		if(isUpperCase(p.text())){ // if p-text in in UPPERCASE
        		p.addClass('bold');    // add class bold
     		}
  		}
	}
});