JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" placeholder="inputText" id="inputText">
<input id='clickMe' type="button" value="alertType">

JavaScript

$('#clickMe').click(function () {
    var inputVal = $("#inputText").val();
    var value = Number(inputVal);

    if (isNaN(value)) {
        alert('not a number');
    } else {
        alert('a number');
    }
});