function generate(count) {
var founded = false,
_sym = 'abcdefghijklmnopqrstuvwxyz1234567890',
str = '';
while(!founded) {
for(var i = 0; i < count; i++) {
str += _sym[parseInt(Math.random() * (_sym.length))];
}
base.getID(string, function(err, res) {
if(!res.length) {
founded = true; // How to do it?
}
});
}
return str;
}
如何设置一个变量值与数据库查询回调?我该怎么做呢?
当前回答
从14.17.0开始，你现在可以使用内置的加密模块来生成uuid (UUIDv4 flavour):
const { randomUUID } = require('crypto'); // Added in: node v14.17.0
console.log(randomUUID());
// '89rct5ac2-8493-49b0-95d8-de843d90e6ca'
你可以探索更多 https://nodejs.org/api/crypto.html#crypto_crypto_randomuuid_options
注意:密码。randomUUID比uuid快三倍。而且不需要增加额外的依赖。
其他回答
我的5美分:
const crypto = require('crypto');
const generateUuid = () => {
return [4, 2, 2, 2, 6] // or 8-4-4-4-12 in hex
.map(group => crypto.randomBytes(group).toString('hex'))
.join('-');
};
遗憾的是，Pono的字符串缺少连字符，所以它不符合uuid标准，这是我相信大多数人来这里的原因。
> generateUuid();
'143c8862-c212-ccf1-e74e-7c9afa78d871'
> generateUuid();
'4d02d4d6-4c0d-ea6b-849a-208b60bfb62e'
安装NPM uuid包(来源:https://github.com/uuidjs/uuid):
npm install uuid
并在你的代码中使用它，例如ES6导入:
import { v4 as uuidv4, v6 as uuidv6 } from 'uuid';
uuidv4();
uuidv6();
或者使用CommonJS需要:
const {
v1: uuidv1,
v4: uuidv4,
} = require('uuid');
uuidv1(); // -> '6c84fb90-12c4-11e1-840d-7b25c5ee775a'
uuidv4(); // -> '110ec58a-a0f2-4ac4-8393-c866d813b8d1'
For
我想用这个
class GUID { Generate() { const hex = "0123456789ABCDEF"; const model = "xxxxxxxx-xxxx-4xxx-xxxx-xxxxxxxxxxxx"; var str = ""; for (var i = 0; i < model.length; i++) { var rnd = Math.floor(Math.random() * hex.length); str += model[i] == "x" ? hex[rnd] : model[i] ; } return str.toLowerCase(); } } console.log(new GUID().Generate()); console.log(new GUID().Generate()); console.log(new GUID().Generate()); console.log(new GUID().Generate()); console.log(new GUID().Generate());
更容易，没有额外的模块
Math.random().toString(26).slice(2)
这里的解决方案是旧的，现在已弃用:https://github.com/uuidjs/uuid#deep-requires-now-deprecated
用这个:
NPM安装uuid
//add these lines to your code
const { v4: uuidv4 } = require('uuid');
var your_uuid = uuidv4();
console.log(your_uuid);
