//返回随机字母

let alpha = "ABCDEFGHIGKLMNOPQRSTUVWXYZ";
console.log(alpha.charAt(Math.floor(Math.random() * alpha.length)));

函数randomstring（L）{var s=“”；var randomchar=函数（）{var n=数学地板（Math.random（）*62）；如果（n<10）返回n//1-10如果（n<36）返回String.fromCharCode（n+55）//A-Z型return String.fromCharCode（n+61）//a-z型}而（s.length<L）s+=randomchar（）；返回s；}console.log（随机字符串（5））；

下面这个怎么样。。。这将产生真正随机的值：

function getRandomStrings(length) {
  const value = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  const randoms = [];
  for(let i=0; i < length; i++) {
     randoms.push(value[Math.floor(Math.random()*value.length)]);
  }
  return randoms.join('');
}

但如果您在ES6中寻找一个较短的语法：

const getRandomStrings = length => Math.random().toString(36).substr(-length);

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>

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;

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））；