<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
// do while不管条件如何，先运行一遍代码
var n=1;
do{
console.log("hello world");
n++;
}while(n<10)
</script>
</body>
</html>
