准备一个包含了[a-z],[A-Z],[0-9],[!@#$%^&*]这些的字符串key，通过设置的密码长度来进行循环，每次都从 key里随机取一个值拼接到新字符串keys里，这样一个新密码就诞生了。
| 密码生成器 | |
| 密码长度 | |
| 密码 | |
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>密码生成器</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
table{margin: 250px auto;text-align: center; border-right:1px solid #ddd;border-bottom:1px solid #ddd;}
thead,tfoot{background: #fff;font-weight: 800;}
tbody{background: #f5f5f5;}
table td{border-left:1px solid #ddd;border-top:1px solid #ddd;padding: 5px 10px;}
table tbody td input{width:270px;}
</style>
</head>
<body>
<table border="0" cellspacing="0" cellpadding="0">
<thead>
<tr><td colspan="2">密码生成器</td></tr>
</thead>
<tbody>
<tr>
<td>密码长度</td>
<td><input type="text" value="32" placeholder="密码长度"></td>
</tr>
<tr>
<td>密码</td>
<td><input type="text" value="" placeholder="密码"></td>
</tr>
</tbody>
<tfoot>
<tr><td colspan="2"><input type="button" value="生成"></td></tr>
</tfoot>
</table>
<script>
var input = document.getElementsByTagName('input');
input[2].onclick = function () {
input[1].value = rand(input[0].value);
}
function rand (leng) {
var key = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*';
var keys = '';
for (i = 0; i < leng; i++) {
var keyl = parseInt(key.length * Math.random());
keys += key[keyl];
}
return keys;
}
</script>
</body>
</html>
