for循环简单应用(1)
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
window.onload = function (){
// +=
/*
document.body.innerHTML += '<input type="button" value="按钮" />';
document.body.innerHTML += '<input type="button" value="按钮" />';
document.body.innerHTML += '<input type="button" value="按钮" />';
*/
// 性能有问题！！！
var str = '';
for( var i=0; i<6000; i++ ){
// document.body.innerHTML += '<input type="button" value="按钮" />';
str += '<input type="button" value="按钮" />';
}
document.body.innerHTML = str;
};
</script>
</head>
<body>
</body>
</html>
