<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <style> img { display: inline-block; width: 100px; height: 150px; } </style> </head> <body> <div id="app"></div> <script> window.onload = function () { var app = document.getElementById(‘app‘); // 追加50个灯泡 for (var i = 0; i < 50; i++) { app.innerHTML += ‘<img src="images/bright.jpg" >‘; } var imgs = document.getElementsByTagName(‘img‘); for (var i = 0; i < imgs.length; i++) { imgs[i].flag = true; // 每一个灯泡都配备一个开关 默认值都是 true-亮 imgs[i].onmouseover = function () { if (this.flag) { // 判断 当前 img 身上的开关状态 this.src = ‘images/dark.jpg‘; this.flag = false; // 改变当前img 身上开关状态 } else { this.src = ‘images/bright.jpg‘; this.flag = true; } } } } </script> </body> </html>
原文：https://www.cnblogs.com/shihaiying/p/13229837.html