JavaScript：硬编码生成随机数，随机字符串

var next_chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678';    /****删除一些混淆字符oOLl,9gq,Vv,Uu,I1****/
var next_length = next_chars.length;
var next_random = '';
for (i = 0; i < 6; i++) {
    next_random += next_chars.charAt(Math.floor(Math.random() * next_length));
}