JavaScript生成随机数的4种自定义函数分享

/**@desc:生成随机字符串*@remark:toString方法可以接收一个基数作为参数的原理，这个基数从2到36封顶。如果不指定，默认基数是10进制*/function generateRandomAlphaNum(len) {  var rdmString = "";  for (; rdmString.length < len; rdmString += Math.random().toString(36).substr(2));  return rdmString.substr(0, len);}

//JS生成GUID函数,类似.net中的NewID(); function S4() {  return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);}function NewGuid() {  return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());}

//JS生成GUID函数,类似.net中的NewID(); function newGuid() {  var guid = "";  for (var i = 1; i <= 32; i++) {    var n = Math.floor(Math.random() * 16.0).toString(16);    guid += n;    if ((i == 8) || (i == 12) || (i == 16) || (i == 20))      guid += "-";  }  return guid;}

/**@desc:生成随机字符串*@demo:console.log(ranStr());*/;(function(){  //数字0-9，大写字母，小写字母，ASCII或UNICODE编码（十进制），共62个  var charCodeIndex = [[48,57],[65,90],[97,122]];  var charCodeArr = [];  function getBetweenRound(min,max){    return Math.floor(min+Math.random()*(max-min));  };  function getCharCode(){    for(var i=0,len=3;i<len;i++){      var thisArr = charCodeIndex[i];      for(var j=thisArr[0],thisLen=thisArr[1];j<=thisLen;j++){        charCodeArr.push(j);      }    }  }  function ranStr(slen){    slen = slen || 20;    charCodeArr.length<62 && getCharCode();    var res = [];    for(var i=0;i<slen;i++){      var index = getBetweenRound(0,61);      res.push(String.fromCharCode(charCodeArr[index]));    }    return res.join('');  };  this.ranStr = ranStr;})();