JSFiddle - React, Tailwind, and code Playground

HTML

<div contenteditable>
  <b>Lorem</b> Ipsum <b>dolor</b> sit...
</div>

<br/>

<button> Run</button>
bold = <span class="result">...</span> found

CSS

.result{
    color :red;
}

JavaScript

$(document).ready(function(){
  
    $("button").click(function(){
        var a = $("b").length;
        $(".result").text(a);      
    });
});