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

如果您无法键入字符集,使用String.fromCharCode和范围内的Math.random可以在任何Unicode代码点范围内创建随机字符串。例如,如果您想要17个随机藏文字符,可以输入ranstr(17,0xf00,0xfff),其中(0xf00,0xff)对应于藏文Unicode块。在我的实现中,如果不指定代码点范围,生成器将输出ASCII文本。函数ranchar(a,b){a=(a==未定义?0:a);b=(b===未定义?127:b);return String.fromCharCode(Math.floor(Math.random()*(b-a)+a));}函数transtr(len,a,b){a=a||32;var结果=“”;对于(var i=0;i<len;i++){结果+=ranchar(a,b)}返回结果;}//以下是随机Unicode块的一些示例console.log('拉丁语基本块:'+transtr(10,0x000,0x007f))console.log('拉丁语-1增补块:'+transtr(10,0x080,0x0ff))console.log('货币符号块中:'+transtr(10,0x20a0,0x20cf))console.log('在类字母符号块中:'+transtr(10,0x2100,0x214f))console.log('在Dingbats块中:'+transtr(10,0x2700,0x27bf))

其他回答

function generate(length) {
  var letters = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","0","1","2","3","4","5","6","7","8","9"];
  var IDtext = "";
  var i = 0;
  while (i < length) {
    var letterIndex = Math.floor(Math.random() * letters.length);
    var letter = letters[letterIndex];
    IDtext = IDtext + letter;
    i++;
  }
  console.log(IDtext)
}

这是我创建的方法。它将创建一个包含大小写字符的字符串。此外,我还包含了将创建字母数字字符串的函数。

工作示例:http://jsfiddle.net/greatbigmassive/vhsxs/(仅限alpha)http://jsfiddle.net/greatbigmassive/PJwg8/(字母数字)

function randString(x){
    var s = "";
    while(s.length<x&&x>0){
        var r = Math.random();
        s+= String.fromCharCode(Math.floor(r*26) + (r>0.5?97:65));
    }
    return s;
}

2015年7月升级这做了同样的事情,但更有意义,包括所有字母。

var s = "";
while(s.length<x&&x>0){
    v = Math.random()<0.5?32:0;
    s += String.fromCharCode(Math.round(Math.random()*((122-v)-(97-v))+(97-v)));
}

这个小巧的小把戏怎么样?

var possible = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
var stringLength = 5;

function pickRandom() {
    return possible[Math.floor(Math.random() * possible.length)];
}

var randomString = Array.apply(null, Array(stringLength)).map(pickRandom).join('');

您需要Array.apply来将空数组变为未定义的数组。

如果您正在为ES2015进行编码,那么构建阵列会简单一些:

var randomString = Array.from({ length: stringLength }, pickRandom).join('');

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);

这里有一些简单的一行。更改新阵列(5)以设置长度。

包括0-9a-z

new Array(5).join().replace(/(.|$)/g, function(){return ((Math.random()*36)|0).toString(36);})

包括0-9a-zA-Z

new Array(5).join().replace(/(.|$)/g, function(){return ((Math.random()*36)|0).toString(36)[Math.random()<.5?"toString":"toUpperCase"]();});

ES6编码(0-9a-z)

Array(5).fill().map(n=>(Math.random()*36|0).toString(36)).join('')