random password generator tutorial javascrpt alwys include special caharcets code example

Example 1: javascript password generator

var Password = {
 
  _pattern : /[a-zA-Z0-9_\-\+\.]/,
  
  
  _getRandomByte : function()
  {
    // http://caniuse.com/#feat=getrandomvalues
    if(window.crypto && window.crypto.getRandomValues) 
    {
      var result = new Uint8Array(1);
      window.crypto.getRandomValues(result);
      return result[0];
    }
    else if(window.msCrypto && window.msCrypto.getRandomValues) 
    {
      var result = new Uint8Array(1);
      window.msCrypto.getRandomValues(result);
      return result[0];
    }
    else
    {
      return Math.floor(Math.random() * 256);
    }
  },
  
  generate : function(length)
  {
    return Array.apply(null, {'length': length})
      .map(function()
      {
        var result;
        while(true) 
        {
          result = String.fromCharCode(this._getRandomByte());
          if(this._pattern.test(result))
          {
            return result;
          }
        }        
      }, this)
      .join('');  
  }    
    
};

Example 2: javascript password generator

<input type='text' id='p'/><br/>
<input type='button' value ='generate' onclick='document.getElementById("p").value = Password.generate(16)'>