如何在JavaScript中创建GUID(全球独特识别器)?GUID/UUID应该至少有32个字符,并且应该保持在ASCII范围内,以避免在通过它们时遇到麻烦。
我不确定在所有浏览器上有哪些习惯,如何“随机”和种植内置的随机号码发电机等。
如何在JavaScript中创建GUID(全球独特识别器)?GUID/UUID应该至少有32个字符,并且应该保持在ASCII范围内,以避免在通过它们时遇到麻烦。
我不确定在所有浏览器上有哪些习惯,如何“随机”和种植内置的随机号码发电机等。
当前回答
function randomHex(length) {
var random_string = '';
if(!length){
length = 1;
}
for(var i=0; i<length; i+=1){
random_string += Math.floor(Math.random() * 15).toString(16);
}
return random_string;
}
function guid() {
return randomHex(8);
}
其他回答
简单的JavaScript作为这个问题的最佳答案的组合。
var crypto = window.crypto || window.msCrypto || null; // IE11 fix var Guid = Guid || (function() { var EMPTY = '00000000-0000-0000-0000-000000000000'; var _padLeft = function(paddingString, width, replacementChar) { return paddingString.length >= width ? paddingString : _padLeft(replacementChar + paddingString, width, replacementChar || ' '); }; var _s4 = function(number) { var hexadecimalResult = number.toString(16); return _padLeft(hexadecimalResult, 4, '0'); }; var _cryptoGuid = function() { var buffer = new window.Uint16Array(8); crypto.getRandomValues(buffer); return [_s4(buffer[0]) + _s4(buffer[1]), _s4(buffer[2]), _s4(buffer[3]), _s4(buffer[4]), _s4(buffer[5]) + _s4(buffer[6]) + _s4(buffer[7])].join('-'); }; var _guid = function() { var currentDateMilliseconds = new Date().getTime(); return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(currentChar) { var randomChar = (currentDateMilliseconds + Math.random() * 16) % 16 | 0; currentDateMilliseconds = Math.floor(currentDateMilliseconds / 16); return (currentChar === 'x' ? randomChar : (randomChar & 0x7 | 0x8)).toString(16); }); }; var create = function() { var hasCrypto = crypto != 'undefined' && crypto !== null, hasRandomValues = typeof(window.crypto.getRandomValues) != 'undefined'; return (hasCrypto && hasRandomValues) ? _cryptoGuid() : _guid(); }; return { newGuid: create, empty: EMPTY }; })(); // DEMO: Create and show GUID console.log('1. New Guid: ' + Guid.newGuid()); // DEMO: Show empty GUID console.log('2. Empty Guid: ' + Guid.empty);
使用:
主持人( )
“c6c2d12f-d76b-5739-e551-07e6de5b0807”
公平 公平
“00000000-0000-0000-0000-00000000”
UUID 目前有附加标准图书馆的提议,可在这里支持 ECMAScript 提议: JavaScript 标准图书馆 UUID
提案包括有 UUID 如下:
// We're not yet certain as to how the API will be accessed (whether it's in the global, or a
// future built-in module), and this will be part of the investigative process as we continue
// working on the proposal.
uuid(); // "52e6953d-edbe-4953-be2e-65ed3836b2f0"
此实施跟随与 V4 随机 UUID 世代相同的布局: https://www.npmjs.com/package/uuid
const uuidv4 = require('uuid/v4');
uuidv4(); // ⇨ '1b9d6bcd-bbfd-4b2d-9b5d-ab8dfbbd4bed'
我认为值得一提的是,通过在标准图书馆中正式实施,可以通过此节省多少带宽,这也是值得一提的。
12 kB uuid 模块从 npm > 62,000,000 次每月下载(2019 年 6 月);在标准图书馆中提供它最终节省 TB 的带宽全球。
不要使用 Math.random 在任何情况下,因为它产生一个非加密的随机数字来源。
下面的解决方案使用crypto.getRandomValues
function uuidv4() {
return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, (c) => {
// tslint:disable-next-line: no-bitwise
const r =
(window.crypto.getRandomValues(new Uint32Array(1))[0] *
Math.pow(2, -32) * 16) |
0;
// tslint:disable-next-line: no-bitwise
const v = c === "x" ? r : (r & 0x3) | 0x8;
return v.toString(16);
});
}
此链接有助于您了解由 Fortify Scanner 投下的不安全的随机性。
下面的版本是布罗法的答案的调整,但更新,包括一个“真实”随机功能,使用加密图书馆在可用的地方,以及Alea()功能作为落后。
Math.log2 = Math.log2 || function(n){ return Math.log(n) / Math.log(2); }
Math.trueRandom = (function() {
var crypt = window.crypto || window.msCrypto;
if (crypt && crypt.getRandomValues) {
// If we have a crypto library, use it
var random = function(min, max) {
var rval = 0;
var range = max - min;
if (range < 2) {
return min;
}
var bits_needed = Math.ceil(Math.log2(range));
if (bits_needed > 53) {
throw new Exception("We cannot generate numbers larger than 53 bits.");
}
var bytes_needed = Math.ceil(bits_needed / 8);
var mask = Math.pow(2, bits_needed) - 1;
// 7776 -> (2^13 = 8192) -1 == 8191 or 0x00001111 11111111
// Create byte array and fill with N random numbers
var byteArray = new Uint8Array(bytes_needed);
crypt.getRandomValues(byteArray);
var p = (bytes_needed - 1) * 8;
for(var i = 0; i < bytes_needed; i++ ) {
rval += byteArray[i] * Math.pow(2, p);
p -= 8;
}
// Use & to apply the mask and reduce the number of recursive lookups
rval = rval & mask;
if (rval >= range) {
// Integer out of acceptable range
return random(min, max);
}
// Return an integer that falls within the range
return min + rval;
}
return function() {
var r = random(0, 1000000000) / 1000000000;
return r;
};
} else {
// From https://web.archive.org/web/20120502223108/http://baagoe.com/en/RandomMusings/javascript/
// Johannes Baagøe <baagoe@baagoe.com>, 2010
function Mash() {
var n = 0xefc8249d;
var mash = function(data) {
data = data.toString();
for (var i = 0; i < data.length; i++) {
n += data.charCodeAt(i);
var h = 0.02519603282416938 * n;
n = h >>> 0;
h -= n;
h *= n;
n = h >>> 0;
h -= n;
n += h * 0x100000000; // 2^32
}
return (n >>> 0) * 2.3283064365386963e-10; // 2^-32
};
mash.version = 'Mash 0.9';
return mash;
}
// From http://baagoe.com/en/RandomMusings/javascript/
function Alea() {
return (function(args) {
// Johannes Baagøe <baagoe@baagoe.com>, 2010
var s0 = 0;
var s1 = 0;
var s2 = 0;
var c = 1;
if (args.length == 0) {
args = [+new Date()];
}
var mash = Mash();
s0 = mash(' ');
s1 = mash(' ');
s2 = mash(' ');
for (var i = 0; i < args.length; i++) {
s0 -= mash(args[i]);
if (s0 < 0) {
s0 += 1;
}
s1 -= mash(args[i]);
if (s1 < 0) {
s1 += 1;
}
s2 -= mash(args[i]);
if (s2 < 0) {
s2 += 1;
}
}
mash = null;
var random = function() {
var t = 2091639 * s0 + c * 2.3283064365386963e-10; // 2^-32
s0 = s1;
s1 = s2;
return s2 = t - (c = t | 0);
};
random.uint32 = function() {
return random() * 0x100000000; // 2^32
};
random.fract53 = function() {
return random() +
(random() * 0x200000 | 0) * 1.1102230246251565e-16; // 2^-53
};
random.version = 'Alea 0.9';
random.args = args;
return random;
}(Array.prototype.slice.call(arguments)));
};
return Alea();
}
}());
Math.guid = function() {
return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
var r = Math.trueRandom() * 16 | 0,
v = c == 'x' ? r : (r & 0x3 | 0x8);
return v.toString(16);
});
};
ES6 样品
const guid=()=> {
const s4=()=> Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
return `${s4() + s4()}-${s4()}-${s4()}-${s4()}-${s4() + s4() + s4()}`;
}