JavaScript generates random numbers of 4 kinds of custom functions to share _javascript tips

The first of these methods

*
* @desc: Generate a random string
* @remark: The ToString method can receive a cardinality as a parameter of the principle, which is capped from 2 to 36. If not specified, the default cardinality is 10
/function Generaterandomalphanum (len) {
  var rdmstring = "";
  for (; rdmstring.length < len; rdmstring + = Math.random (). toString (2));
  Return rdmstring.substr (0, Len);
}

The second method

JS generates a GUID function, similar to the NEWID in. NET (); 
function S4 () {return
  ((1 + math.random ()) * 0x10000) | 0). toString (+). substring (1);
}

function NewGuid () {return
  (S4 () + S4 () + "-" + S4 () + "-" + S4 () + "-" + S4 () + "-" + S4 () + S4 () + S4 ());
}

The third method

JS generates a GUID function, similar to the NEWID in. NET (); 
function NewGuid () {
  var guid = ' ";
  for (var i = 1; I <= i++) {
    var n = math.floor (Math.random () * 16.0). toString ();
    GUID + N;
    if ((i = = 8) | | (i = = 12) | | (i = = 16) | | (i = =))
      GUID = + "-";
  }
  return GUID;
}

Fourth method

*
* @desc: Generate random string
* @demo: Console.log (Ranstr ());
*
/;(function () {
  //number 0-9, uppercase letters, lowercase letters, ASCII or Unicode encoding (decimal), total 62
  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 | |
    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;
}) ();