JSFiddle - React, Tailwind, and code Playground
JavaScript
show('NaN'); // "old: true new: false"
show(undefined); // "old: true new: false"
show({}); // "old: true new: false"
show('blabla'); // "old: true new: false"
function show(value) {
console.log(`old: ${isNaN(value)} new: ${Number.isNaN(value)}`);
}