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

例如,如果你想要一个随机的DNA序列,你可以循环遍历一个项目数组并递归地将它们添加到字符串变量中:

功能随机DNA(len){len=长度||100var nuc=新阵列(“A”、“T”、“C”、“G”)变量i=0变量n=0s=“”而(i<=len-1){n=数学楼层(Math.random()*4)s+=努克[n]我++}返回s}console.log(随机DNA(5));

其他回答

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))

这是肯定的

<script language="javascript" type="text/javascript">
function randomString() {
 var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
 var string_length = 8;
 var randomstring = '';
 for (var i=0; i<string_length; i++) {
  var rnum = Math.floor(Math.random() * chars.length);
  randomstring += chars.substring(rnum,rnum+1);
 }
 document.randform.randomfield.value = randomstring;
}
</script>

我想这会对你有用:

函数makeid(长度){let result=“”;const characters=‘EFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz0123456789’;常量字符长度=字符长度;让计数器=0;while(计数器<长度){result+=characters.charAt(Math.floor(Math.random()*charactersLength));计数器+=1;}返回结果;}console.log(makeid(5));

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)));
}