<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>HelloWorld</title> <script type="text/javascript"> //借助window.onload事件,在这个页面加载完成后执行程序代码 window.onload = function(){ //获取按钮对象 var btnEle = document.getElementById("btnId"); //给按钮对象绑定单击响应函数 btnEle.onclick = function(){ //弹出警告框 alert("Hello"); }; }; </script> </head> <body> <button id="btnId">SayHello</button> </body> </html>
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>HelloWorld空白</title> <script type="text/javascript"> //main window.onload = function(){ //btnId var btnEle = document.getElementById("btnId"); btnEle.onclick = function(){ //alert() alert("Hello js!!!"); } } </script> </head> <body> <button id="btnId">SayHello</button> </body> </html>