简介:
UUID(Universally Unique IDentifier) 全局惟一标识符。
UUID是一种由算法生成的二进制长度为128位的数字标识符。UUID
的格局为“xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”，其中的 x 是 0-9 或 a-f
范畴内的一个32位十六进制数。在现实状况下，任何计算机和计算机集群都不会生成两个雷同的UUID。
1.第一种
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); });}guid() // "a1ca0f7b-51bd-4bf3-a5d5-6a74f6adc1c7"2.第二种
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;}uuid() // "ffb7cefd-02cb-4853-8238-c0292cf988d5"3.第三种
function guid2() { function S4() { return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1); } return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());}guid2() // "748eea29-f842-4af9-a552-e1e1aa3ed979"4.第四种
// 指定长度和基数function uuid2(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('');}uuid2(16, 16) // "277571702EE33E11"5.第五种
阐明:生成32位UUID办法
function uuid() { var s = []; var hexDigits = "0123456789abcdef"; for (var i = 0; i < 32; 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;}