JS 生成 UUID/GUID

全局唯一标识符（GUID，Globally Unique Identifier）也称作 UUID(Universally Unique IDentifier) 。

GUID 是一种由算法生成的二进制长度为 128 位的数字标识符。GUID 的格式为 xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx，其中的 x 是 0-9 或 a-f 范围内的一个 32 位十六进制数。在理想情况下，任何计算机和计算机集群都不会生成两个相同的 GUID。

GUID 的总数达到了 2^128（3.4×10^38） 个，所以随机生成两个相同 GUID 的可能性非常小，但并不为 0。GUID 一词有时也专指微软对 UUID 标准的实现。

node.js 可以使用 node-uuid 模块，以下是我自己实现的方法

算法 1

javascript

function uuid() {
  var s = [];
  var hexDigits = "0123456789abcdef";
  for (var i = 0; i < 36; i++) {
    s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
  }
  s[14] = "4"; // bits 12-15 of the time_hi_and_version field to 0010
  s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1); // bits 6-7 of the clock_seq_hi_and_reserved to 01
  s[8] = s[13] = s[18] = s[23] = "-";

  var uuid = s.join("");
  return uuid;
}

function uuid() {
  var s = [];
  var hexDigits = "0123456789abcdef";
  for (var i = 0; i < 36; i++) {
    s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
  }
  s[14] = "4"; // bits 12-15 of the time_hi_and_version field to 0010
  s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1); // bits 6-7 of the clock_seq_hi_and_reserved to 01
  s[8] = s[13] = s[18] = s[23] = "-";

  var uuid = s.join("");
  return uuid;
}

算法 2

javascript

function guid() {
  return "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx".replace(/[x]/g, function (c) {
    var r = (Math.random() * 16) | 0;
    var v = c == "x" ? r : c;
    return v.toString(16);
  });
}

function guid() {
  return "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx".replace(/[x]/g, function (c) {
    var r = (Math.random() * 16) | 0;
    var v = c == "x" ? r : c;
    return v.toString(16);
  });
}

算法 3

javascript

function guid() {
  function S4() {
    return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
  }
  return S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4();
}

function guid() {
  function S4() {
    return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
  }
  return S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4();
}

算法 4

javascript

function uuid(len, radix) {
  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".split("");
  var uuid = [],
    i;
  radix = radix || chars.length;

  if (len) {
    // Compact form
    for (i = 0; i < len; i++) uuid[i] = chars[0 | (Math.random() * radix)];
  } else {
    // rfc4122, version 4 form
    var r;

    // rfc4122 requires these characters
    uuid[8] = uuid[13] = uuid[18] = uuid[23] = "-";
    uuid[14] = "4";

    // Fill in random data.  At i==19 set the high bits of clock sequence as
    // per rfc4122, sec. 4.1.5
    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("");
}

function uuid(len, radix) {
  var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".split("");
  var uuid = [],
    i;
  radix = radix || chars.length;

  if (len) {
    // Compact form
    for (i = 0; i < len; i++) uuid[i] = chars[0 | (Math.random() * radix)];
  } else {
    // rfc4122, version 4 form
    var r;

    // rfc4122 requires these characters
    uuid[8] = uuid[13] = uuid[18] = uuid[23] = "-";
    uuid[14] = "4";

    // Fill in random data.  At i==19 set the high bits of clock sequence as
    // per rfc4122, sec. 4.1.5
    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("");
}

这个可以指定长度和基数。比如

javascript

// 8 character ID (base=2)
uuid(8, 2); //  "01001010"
// 8 character ID (base=10)
uuid(8, 10); // "47473046"
// 8 character ID (base=16)
uuid(8, 16); // "098F4D35"

// 8 character ID (base=2)
uuid(8, 2); //  "01001010"
// 8 character ID (base=10)
uuid(8, 10); // "47473046"
// 8 character ID (base=16)
uuid(8, 16); // "098F4D35"

JS 生成 UUID/GUID ​

算法 1 ​

算法 2 ​

算法 3 ​

算法 4 ​

JS 生成 UUID/GUID

算法 1

算法 2

算法 3

算法 4