uuid 生成器

/**
 * 生成 uuid
 * @param len uuid 长度 默认 16
 * @param radix 字符集长度 默认 62
 * @returns uuid 字符串
 */
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("");
}