For Loop in JavaScript - Lottery Website

Question

I am trying to turn this code into a correct for loop statement, so that I can save my repetitions. I have tried my best to get it done, but I just don\'t know how I can write i

Answer 1

try something like this:

Array.prototype.getDuplicates = function() {
  var cache = {}, results = [], that = this;
  that.forEach(function(item, index) {
      if(!cache.hasOwnProperty(item) && that.lastIndexOf(item) > index) {
          results.push(item);
      }
      cache[item] = true;
  });
  return results;
}

var answers = [luckyNumber, luckyNumber2, luckyNumber3];
var indexes = [answers.indexOf(firstInput), answers.indexOf(secondInput), answers.indexOf(thirdInput)];
if(indexes.indexOf(-1) === -1 && indexes.getDuplicates().length === 0) {
  // alert("Whatever");
}