<html><body><p>单击该按钮可获得基于时间的问候语。</p><button onclick="myFunction()">试一试</button><p id="demo"></p><script>function myFunction() { var time = new Date().getHours(); var greeting; if (time < 10) { greeting = "Good morning"; } else if (time < 20) { greeting = "Good day"; } else { greeting ="Good evening"; }document.getElementById("demo").innerHTML = greeting;}</script></body></html>