JSFiddle - React, Tailwind, and code Playground

HTML

<form name='theform' id='theform' action=''>
    <textarea id='nonumbers' cols='60' rows='10'> </textarea>
</form>

JavaScript

$().ready(function(){
    $("textarea#nonumbers").keyup(removeextra).blur(removeextra);
});
function removeextra() {
    var initVal = $(this).val();
    outputVal = initVal.replace(/[^0-9a-zA-Z]/g,"");       
    if (initVal != outputVal) {
        $(this).val(outputVal);
    }
};