JSFiddle - React, Tailwind, and code Playground

JavaScript

var reIsNumeric = /[0-9]/g;
console.log(reIsNumeric.test(1));  // true
console.log(reIsNumeric.test(22));  // true
console.log(reIsNumeric.test(333));  // true
console.log(reIsNumeric.test(4444));  // true