我想要一个5个字符的字符串,由从集合[a-zA-Z0-9]中随机选取的字符组成。

用JavaScript实现这一点的最佳方法是什么?


当前回答

为后代发布ES6兼容版本。如果这是多次调用,请确保将.length值存储到常量变量中。

// USAGE:
//      RandomString(5);
//      RandomString(5, 'all');
//      RandomString(5, 'characters', '0123456789');
const RandomString = (length, style = 'frictionless', characters = '') => {
    const Styles = {
        'all':          allCharacters,
        'frictionless': frictionless,
        'characters':   provided
    }

    let result              = '';
    const allCharacters     = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const frictionless      = 'ABCDEFGHJKMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz23456789';
    const provided          = characters;

    const generate = (set) => {
        return set.charAt(Math.floor(Math.random() * set.length));
    };

    for ( let i = 0; i < length; i++ ) {
        switch(Styles[style]) {
            case Styles.all:
                result += generate(allCharacters);
                break;
            case Styles.frictionless:
                result += generate(frictionless);
                break;
            case Styles.characters:
                result += generate(provided);
                break;
        }
    }
    return result;
}

export default RandomString;

其他回答

随机unicode字符串

此方法将返回一个随机字符串,其中包含任何受支持的unicode字符,这不是OP要求的100%,而是我想要的:

function randomUnicodeString(length){
    return Array.from({length: length}, ()=>{
        return String.fromCharCode(Math.floor(Math.random() * (65536)))
    }).join('')
}

根本原因

这是谷歌搜索“随机字符串javascript”时的最高结果,但OP只要求a-zA-Z0-9。

为后代发布ES6兼容版本。如果这是多次调用,请确保将.length值存储到常量变量中。

// USAGE:
//      RandomString(5);
//      RandomString(5, 'all');
//      RandomString(5, 'characters', '0123456789');
const RandomString = (length, style = 'frictionless', characters = '') => {
    const Styles = {
        'all':          allCharacters,
        'frictionless': frictionless,
        'characters':   provided
    }

    let result              = '';
    const allCharacters     = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const frictionless      = 'ABCDEFGHJKMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz23456789';
    const provided          = characters;

    const generate = (set) => {
        return set.charAt(Math.floor(Math.random() * set.length));
    };

    for ( let i = 0; i < length; i++ ) {
        switch(Styles[style]) {
            case Styles.all:
                result += generate(allCharacters);
                break;
            case Styles.frictionless:
                result += generate(frictionless);
                break;
            case Styles.characters:
                result += generate(provided);
                break;
        }
    }
    return result;
}

export default RandomString;

生成任意数量的十六进制字符(例如32):

(function(max){let r='';for(let i=0;i<max/13;i++)r+=(Math.random()+1).toString(16).substring(2);return r.substring(0,max).toUpperCase()})(32);

为了满足要求[a-zA-Z0-9]和5个字符的长度,使用

对于浏览器:

btoa(Math.random().toString()).substring(10,15);

对于NodeJS:

Buffer.from(Math.random().toString()).toString("base64").substring(10,15);

将出现小写字母、大写字母和数字。

(字体兼容)

我只需要编写一个简单的包来生成具有给定大小、种子和掩码的随机令牌。仅供参考。

@sibevin/随机令牌-https://www.npmjs.com/package/@sibevin/随机令牌

import { RandomToken } from '@sibevin/random-token'

RandomToken.gen({ length: 32 })
// JxpwdIA37LlHan4otl55PZYyyZrEdsQT

RandomToken.gen({ length: 32, seed: 'alphabet' })
// NbbtqjmHWJGdibjoesgomGHulEJKnwcI

RandomToken.gen({ length: 32, seed: 'number' })
// 33541506785847193366752025692500

RandomToken.gen({ length: 32, seed: 'oct' })
// 76032641643460774414624667410327

RandomToken.gen({ length: 32, seed: 'hex' })
// 07dc6320bf1c03811df7339dbf2c82c3

RandomToken.gen({ length: 32, seed: 'abc' })
// bcabcbbcaaabcccabaabcacbcbbabbac

RandomToken.gen({ length: 32, mask: '123abcABC' })
// vhZp88dKzRZGxfQHqfx7DOL8jKTkWUuO