JSFiddle - React, Tailwind, and code Playground

by Brad Christie

CSS

b{
    display: inline-block;
    width: 150px;
}

JavaScript

var tests = ['apple',
             '4',
             '5.6',
             'v8',
             'hello, world!',
             '7even',
             '-156',
             '-5216.056',
             '656-5651',
            '-6'];

function IsNumeric(n){
    // any valid number
    //return /^-?\d+(?:\.\d+)?$/.test(n);

    // only positive numbers
    //return /^\d+(?:\.\d+)?$/.test(n);

    // only positive whole numbers
    return /^\d+$/.test(n);
}
$.each(tests,function(i,t){
    var s = $('<span>');
    $('<p>').html('<b>'+t+'</b> ')
      .append(IsNumeric(t)?s.text('pass').css('color','green'):s.text('fail').css('color','red'))
      .appendTo('body');
});