巧用数组实现多个内容切换

先看下我开始写的代码吧：

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>切换红绿蓝</title>
 6     <style>
 7         #div{
 8             width: 100px;
 9             height:100px;
10             background-color: red;
11         }
12     </style>
13 </head>
14 <body>
15 <div id="div"></div>
16 <script src="main.js"></script>
17 </body>
18 </html>

html

 1 /**
 2  * Created by Administrator on 2016/8/8.
 3  */
 4 (function () {
 5 
 6     var div = document.getElementById("div");
 7     var i = 1;
 8 
 9     function backgroundColor(color) {
10         var e=div.style.backgroundColor=color;
11         return e;
12     }
13     function ClickToSwitchColor() {
14         if (i % 3 == 0) {
15             backgroundColor("red");
16             // div.style.backgroundColor = "red";
17         } else if (i % 2 == 0) {
18             backgroundColor("blue");
19             // div.style.backgroundColor = "blue";
20         } else {
21             backgroundColor("green");
22             // div.style.backgroundColor = "green";
23         }
24         i++;
25     }
26 
27     div.addEventListener("click", ClickToSwitchColor);
28 
29 })
30 ();

我的代码可以实现，但是没有良好的扩展性，如再添加一中颜色遍不容易。

看下优化的代码吧

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>d</title>
 6     <style>
 7         #div{
 8             width: 100px;
 9             height:100px;
10             background-color: red;
11         }
12     </style>
13 </head>
14 <body>
15 <div id="div"></div>
16 <script src="main01.js"></script>
17 </body>
18 </html>

html

 1 /**
 2  * Created by Administrator on 2016/8/8.
 3  */
 4 (function () {
 5     var colors=["red","blue","pink","yellow","green"];
 6     var div=document.getElementById("div");
 7     var index=0;
 8     div.addEventListener("click",function (event) {
 9         index++;
10         if(index>=colors.length){
11             index=0;
12         }
13         div.style.backgroundColor=colors[index];
14     });
15 })();

如代码，巧用数组，实现颜色切换。

应用这个原理也可以实现图片切换，无非在数组里面放上路径而已。

看下代码吧

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>Title</title>
 6     <style>
 7 
 8 
 9     </style>
10 </head>
11 <body>
12 <div id="div">
13     <img src="1.jpg" id="img1"/>
14 </div>
15 
16 
17 <script src="main.js"></script>
18 </body>
19 </html>

html

 1 /**
 2  * Created by Administrator on 2016/8/8.
 3  */
 4 (function () {
 5     var img = document.getElementById("img1");
 6     var images = ["1.jpg", "2.jpg", "3.jpg"];
 7     var index = 0;
 8     setInterval(function () {
 9         index++;
10         if (index >= images.length) {
11             index = 0;
12         }
13         img.src = images[index];
14     }, 3000);
15 })();