JSFiddle - React, Tailwind, and code Playground
HTML
<div>
<input type="text" style="xxxx" size="40"/>
<input type="text" style="xxxx" size="100"/>
<input type="text" style="xxxx" size="100"/>
<input type="text" style="xxxx" size="40"/>
</div>
JavaScript
$(document).ready(function(){
$("input[size=100]").each(function(){
//how to replace it?
$(this).after('<textarea style="xxxx"></textarea>').remove()
});
});