JSFiddle - React, Tailwind, and code Playground

by mcgrailm

HTML

<input name="number1" type="text" size="1" id="number1" onkeyup="doKeyUpValidation(this)" />

JavaScript

function doKeyUpValidation(txt){
    if(!txt.match(/[-0-9]+/g)){
     alert('Please enter only numbers.');
    }
}