JS生成GUID算法

//算法1


//Js代码 

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


//Js代码 

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);  

    });  

}  
 

//算法3


//Js代码 

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


//Js代码 

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(‘‘);  

}