JSFiddle - React, Tailwind, and code Playground

HTML

<div class="crazy">Text</div>
<div class="crazy">Text</div>
<div class="crdazy">Different Text</div>
<div class="crazy life">Text</div>

JavaScript

function ReplaceContentInContainer(matchClass,content)
{
    var elems = document.getElementsByTagName('*'),i;
    for (i in elems)
    {
        var cn = elems[i].className;
        if(cn && cn.match(new RegExp("(^|\\s)" + matchClass + "(\\s|$)")))
        {
            elems[i].innerHTML = content;
        }
    }
}

//window.onload = function ()
{
    ReplaceContentInContainer("crazy","Different Content");
    ReplaceContentInContainer("life","Overwritten Content");
}