JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>

<h2 id="result">今天中午吃什麼？</h2>
<button onclick="pickFood()">抽籤！</button>

<script>
function pickFood() {
  let foods = ["便當", "炒飯", "牛肉麵", "壽司", "漢堡"];
  let randIndex = Math.floor(Math.random() * foods.length);
  document.getElementById("result").innerText = foods[randIndex];
}
</script>
  
</body>
</html>