一,效果图。

二,代码。
- <!DOCTYPE html>
- <html>
- <head>
- <meta charset="utf-8">
- <title>javascript 条件语句</title>
- </head>
- <body>
- <p>如果时间早于20:00,会获得问候“Good day”.</p>
- <button onclick="myFunction()">点击这里</button>
- <p id="demo"></p>
- <script>
- function myFunction() {
- var x = "";
- var time = new Date().getHours();
- if (time < 20) {
- x = "Goo day";
- }
- document.getElementById("demo").innerHTML = x;
- }
- </script>
- <script type="text/javascript">
- var d = new Date();
- var time = d.getHours();
- if (time < 10) {
- document.write("<b>早上好</b>")
- } else if (time >= 10 && time < 16) {
- document.write("<b>hello world!</b>")
- } else {
- document.write("<b>hello world!</b>")
- }
- </script>
- <p>这个例子演示了if.elseif..else</p>
- </body>
- </html>
参考资料:《菜鸟教程》