Javascript to generate a globally unique identifier (GUID, UUID), guiduuid

Javascript to generate a globally unique identifier (GUID, UUID), guiduuid

A Globally Unique Identifier (GUID, Globally Unique IDentifier) is also called a UUID (Universally Unique Identifier ).

GUID is a 128-bit numeric identifier generated by an algorithm. The GUID format is "xxxxxxxx-xxxx-xxxxxxxxxxxx", where x is a 32-bit hexadecimal number in the range of 0-9 or a-f. Ideally, no computer or computer cluster generates two identical guids.

The total number of guids reaches 2 ^ 128 (3.4 × 10 ^ 38), so the probability of randomly generating two identical guids is very small, but not 0. The term GUID sometimes refers to Microsoft's UUID standard implementation.

When generating some nodes, You need to mark them with a unique ID. There are the following high-pass answers for your reference.

function generateUUID() {var d = new Date().getTime();var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {  var r = (d + Math.random()*16)%16 | 0;  d = Math.floor(d/16);  return (c=='x' ? r : (r&0x3|0x8)).toString(16);});return uuid;};

The following comments: the collision rate in this solution is less than 1/2 ^ 122

In addition, we recommend several algorithms.

Algorithm 2

function guid() {  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {    var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);    return v.toString(16);  });} 

Algorithm 3

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

Algorithm 4

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('');}

You can specify the length and base number. For example

// 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"

Algorithm 5

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;} 

Of course, we recommend algorithm 1 for individuals. Our friends can make choices based on their own needs.

Articles you may be interested in:

• Javascript GUID generator implementation code
• Summary of various algorithms for generating guids using JavaScript
• Each extjs component must have a unique ID. Otherwise, an error occurs.
• Generate GUID using JavaScript (globally unified identifier)
• Implementation example of native JavaScript to generate GUID