JSFiddle - React, Tailwind, and code Playground
HTML
<form action="javascript:checkNum()" id="frm">
<input type="text" name="num" min="0" max="1000" required="requrired" pattern="[\-]*[0-9]{0,3}\.?[0-9]{1,}" />
</form>
<script>
function checkNum(){
alert($("#frm").serialize());
}
</script>