export function uuid(len: number = 16, radix?: number): string {
const chars: string[] = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
const uuid: string[] = [];
let i: number;
const radixS = radix || chars.length;
if (len) {
for (i = 0; i < len; i++) {
uuid[i] = chars[0 | (Math.random() * radixS)];
}
} else {
let r: number;
uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
uuid[14] = '4';
for (i = 0; i < 36; i++) {
if (!uuid[i]) {
r = 0 | (Math.random() * 16);
uuid[i] = chars[i === 19 ? (r & 0x3) | 0x8 : r];
}
}
}
return uuid.join('');
}