生成指定长度的随机字符串
function genRandomString(length) {
const charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
const charsetLength = charset.length;
let v = '';
for (let i = 0; i < length; i++) {
v += charset[Math.floor(Math.random() * charsetLength)];
}
return v;
}
