两行Javascript代码生成UUID的方法

function uuid() {
 var temp_url = URL.createObjectURL(new Blob());
 var uuid = temp_url.toString(); // blob:https://xxx.com/b250d159-e1b6-4a87-9002-885d90033be3
 URL.revokeObjectURL(temp_url);
 return uuid.substr(uuid.lastIndexOf("/") + 1);
}

for (var i = 0; i < 10; ++i) {
 console.log(uuid());
}

// 执行结果如下
// f6ca05c0-fad5-46fc-a237-a8e930e7cb49
// 6a88664e-51e1-48c3-a85e-7bf00467e9e6
// e6050f4c-e86d-4081-9376-099bfbef2c30
// bde3da3c-b318-4498-8a03-9a773afa84bd
// ba0fda03-f806-4c2f-b6f5-1e74a299e603
// 62b2edc3-b09f-4bf9-8dbf-c4d599479a29
// e70c0609-22ad-4493-abcc-0e3445291397
// 920255b2-1838-497d-bc33-56550842b378
// 45559c64-971c-4236-9cfc-706048b60e70
// 4bc4bbb9-1e90-432b-99e8-277b40af92cd

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() {
 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);
 });
}

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;
}