JSFiddle - React, Tailwind, and code Playground

by PhillipLittle

HTML

<!DOCTYPE html>
<html lang="en">

  <head>
    <meta charset="utf-8" />
    <link rel="icon" href="%PUBLIC_URL%/favicon.ico" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <meta name="theme-color" content="#000000" />
    <meta name="description" content="Web site created using create-react-app" />
    <link rel="apple-touch-icon" href="%PUBLIC_URL%/logo192.png" />
    <!--
      manifest.json provides metadata used when your web app is installed on a
      user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
    -->
    <link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
    <!--
      Notice the use of %PUBLIC_URL% in the tags above.
      It will be replaced with the URL of the `public` folder during the build.
      Only files inside the `public` folder can be referenced from the HTML.

      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
      work correctly both with client-side routing and a non-root public URL.
      Learn how to configure a non-root public URL by running `npm run build`.
    -->
    <title>Times Table Tester</title>
  </head>

  <body>
    <noscript>You need to enable JavaScript to run this app.</noscript>
    <div id="root"></div>
    <!--
      This HTML file is a template.
      If you open it directly in the browser, you will see an empty page.

      You can add webfonts, meta tags, or analytics to this file.
      The build step will place the bundled scripts into the <body> tag.

      To begin the development, run `npm start` or `yarn start`.
      To create a production bundle, use `npm run build` or `yarn build`.
    -->
  </body>

</html>

CSS

table {
  border: 1px solid;
  height: 400px;
  align-items: center;
}

tr,
td {
  height: auto;
  border: 1px solid;
}

.emphasized {
  background-color: #04AA6D;
  color: white;
  text-align: center;
  font-weight: bold;
  border: 1px solid black;
}

#timesTablesGrid,
#title,
#controls,
#results {
  text-align: center;
  width: 700px;
  margin: auto;
}

.answer {
  width: 100%;
  height: 100%;
  padding: 0%;
  border: 0px;
  text-align: center;
  margin: auto;
}

.correct {
  background-color: lightgreen;
}

.incorrect {
  background-color: lightcoral;
}

React

import { useState } from 'react';
import './App.css';

function Game() {
  const xFactors = shuffle([1,2,3,4,5])
  const yFactors = shuffle([1,2,3,4,5])
  const [isShownGrid, setIsShownGrid] = useState(false)
  const [canEvaluateGrid, setCanEvaluateGrid] = useState(false)
  const [canGenerateGrid, setCanGenerateGrid] = useState(true)
  const [timeGenerated, setTimeGenerated] = useState(Number)
  //const [timeEvaluated, setTimeEvaluated] = useState(Number)

  function shuffle(array) {
    //shuffles the given array
    //note that this overwrites the original array
    return array.sort(() => Math.random() - 0.5);
  }

  const generateGrid = event => {
    setIsShownGrid(true)
    setCanEvaluateGrid(true)
    setCanGenerateGrid(false)
    setTimeGenerated(Date.now)
  }

  function evaluateGrid(e) {
    e.preventDefault()
    let timeEvaluated = Date.now()
    showResults(timeEvaluated)
  }

  function showResults({timeEvaluated}) {
    let timeSpent = timeEvaluated - timeGenerated
    alert('Evaluating answers...\nTime generated: ' +timeGenerated +'\nTime evaluated: '+timeEvaluated + '\nTime spent: ' +timeSpent)
  }

  return (
    <div className='game'>
      <form onSubmit={evaluateGrid}>
        <h1>Times Tables Tester</h1>
        <button disabled={!canGenerateGrid} onClick={generateGrid}>Generate Grid</button><button disabled={!canEvaluateGrid} onClick={evaluateGrid}>Evaluate Grid</button>
        <div className='game-grid'>
        {isShownGrid && (
          <Grid xFactors={xFactors} yFactors={yFactors} />
        )}
        </div>
      </form>
    </div>
  )
}

function Grid({xFactors, yFactors}) {
    
  return (
    <table id='timesTablesGrid'>
      <thead>
        <tr>
          <th className='emphasized'>X</th>
          {xFactors.map((xFactor) => {
            return (
              <th className='emphasized'>{xFactor}</th>
            )
          })}
        </tr>
      </thead>
      <tbody>
        {yFactors.map((yFactor) => {
          return (
...