JSFiddle - React, Tailwind, and code Playground

HTML

<form id="validate">
<input type="text" name="numberInput" id="numberInput" /> 
<input type="submit" value="Submit" />
</form>

CSS

#validate { padding:20px;}

JavaScript

function validate(number) {
    var isValid = false;
    valueFormat = new RegExp('^[0-9]+(\.[0-9][0-9])$');               
    isValid = valueFormat.test(number);
    return isValid;
}
    
$(document).ready(function() {
    var testNumber;
    var result;
    $('#validate').submit(function(e) {
        e.preventDefault();
        testNumber = $('#numberInput').val();
        result = validate(testNumber);
        alert(result);
    });
});