To get an array of randomly selected alpha-numeric characters, in JavaScript.

Random-alphanumeric-strings

/**
 * @title: Random-alphanumeric-strings
 * @author: Shahzad Nawaz
 * @dated: 7/16/2015.
 */
 
//e.g #1
var sixLenstrings = getRandomStrings(6, 2);
console.log(sixLenstrings);
// output: ["UlTl14", "JZRbSS"]

//e.g #2
var threeLenstrings = getRandomStrings(3, 7);
console.log(threeLenstrings);
// output: ["gE3", "fO1", "AZT", "W37", "ntA", "E9Q", "hzG"]

//function that returns strings array.
function getRandomStrings(stringLen, totalStrings) {
  var item, items, possible;
  
  //possible characters to include in creating random strings - alpha-numeric
  possible = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  
  items = [];
  for (var i = 0; i < totalStrings; i++) {
      item = "";
      
      for (var c = 0; c < stringLen; c++) {
          item += possible.charAt(Math.floor(Math.random() * possible.length));
      }
      
      items.push(item);
  }
  
  return items;
}