代码一： /*!Math.uuid.js (v1.4) http://www.broofa.com mailto:robert@broofa.com   Copyright (c) 2010 Robert Kieffer Dual licensed under the MIT and GPL licenses. */   /*  * Generate a random uuid.  *  * USAGE: Math.uuid(length, radix)  *   length - the desired number of characters  *   radix  - the number of allowable values for each character.  *  * EXAMPLES:  *   // No arguments  - returns RFC4122, version 4 ID  *   >>> Math.uuid()  *   "92329D39-6F5C-4520-ABFC-AAB64544E172"  *  *   // One argument - returns ID of the specified length  *   >>> Math.uuid(15)     // 15 character ID (default base=62)  *   "VcydxgltxrVZSTV"  *  *   // Two arguments - returns ID of the specified length, and radix. (Radix must be <= 62)  *   >>> Math.uuid(8, 2)  // 8 character ID (base=2)  *   "01001010"  *   >>> Math.uuid(8, 10) // 8 character ID (base=10)  *   "47473046"  *   >>> Math.uuid(8, 16) // 8 character ID (base=16)  *   "098F4D35"  */ (function() {   // Private array of chars to use   var CHARS = ‘0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz‘.split(‘‘);     Math.uuid = function (len, radix) {     var chars = CHARS, 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(‘‘);   };     // A more performant, but slightly bulkier, RFC4122v4 solution.  We boost performance   // by minimizing calls to random()   Math.uuidFast = function() {     var chars = CHARS, uuid = new Array(36), rnd=0, r;     for (var i = 0; i < 36; i++) {       if (i==8 || i==13 ||  i==18 || i==23) {         uuid[i] = ‘-‘;       } else if (i==14) {         uuid[i] = ‘4‘;       } else {         if (rnd <= 0x02) rnd = 0x2000000 + (Math.random()*0x1000000)|0;         r = rnd & 0xf;         rnd = rnd >> 4;         uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];       }     }     return uuid.join(‘‘);   };     // A more compact, but less performant, RFC4122v4 solution:   Math.uuidCompact = function() {     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);     });   }; })(); 调用方法：Math.uuid() 代码二： //On creation of a UUID object, set it‘s initial value function UUID(){     this.id = this.createUUID(); } // When asked what this Object is, lie and return it‘s value UUID.prototype.valueOf = function(){ return this.id; }; UUID.prototype.toString = function(){ return this.id; }; // // INSTANCE SPECIFIC METHODS // UUID.prototype.createUUID = function(){     //     // Loose interpretation of the specification DCE 1.1: Remote Procedure Call     // since JavaScript doesn‘t allow access to internal systems, the last 48 bits     // of the node section is made up using a series of random numbers (6 octets long).     //      var dg = new Date(1582, 10, 15, 0, 0, 0, 0);     var dc = new Date();     var t = dc.getTime() - dg.getTime();     var tl = UUID.getIntegerBits(t,0,31);     var tm = UUID.getIntegerBits(t,32,47);     var thv = UUID.getIntegerBits(t,48,59) + ‘1‘; // version 1, security version is 2     var csar = UUID.getIntegerBits(UUID.rand(4095),0,7);     var csl = UUID.getIntegerBits(UUID.rand(4095),0,7);     // since detection of anything about the machine/browser is far to buggy,     // include some more random numbers here     // if NIC or an IP can be obtained reliably, that should be put in     // here instead.     var n = UUID.getIntegerBits(UUID.rand(8191),0,7) +             UUID.getIntegerBits(UUID.rand(8191),8,15) +             UUID.getIntegerBits(UUID.rand(8191),0,7) +             UUID.getIntegerBits(UUID.rand(8191),8,15) +             UUID.getIntegerBits(UUID.rand(8191),0,15); // this last number is two octets long     return tl + tm  + thv  + csar + csl + n; }; //Pull out only certain bits from a very large integer, used to get the time //code information for the first part of a UUID. Will return zero‘s if there //aren‘t enough bits to shift where it needs to. UUID.getIntegerBits = function(val,start,end){     var base16 = UUID.returnBase(val,16);     var quadArray = new Array();     var quadString = ‘‘;     var i = 0;     for(i=0;i<base16.length;i++){         quadArray.push(base16.substring(i,i+1));        }     for(i=Math.floor(start/4);i<=Math.floor(end/4);i++){         if(!quadArray[i] || quadArray[i] == ‘‘) quadString += ‘0‘;         else quadString += quadArray[i];     }     return quadString; }; //Replaced from the original function to leverage the built in methods in //JavaScript. Thanks to Robert Kieffer for pointing this one out UUID.returnBase = function(number, base){     return (number).toString(base).toUpperCase(); }; //pick a random number within a range of numbers //int b rand(int a); where 0 <= b <= a UUID.rand = function(max){     return Math.floor(Math.random() * (max + 1)); }; 调用方法：UUID.prototype.createUUID()