Find MARVEL characters without images

gistfile1.js

function getRandomBetween(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

var apiKey = 'apikey=ed23113a7ebab2304b0aad655ec41c6a';
var totalCharacters = 1485;
var randomOffset = getRandomBetween(1, totalCharacters);
//var randomOffset = 1341;
var idsOfCharsWithoutImage = [];
var imageNotAvailable = 'image_not_available';

var offset = 0;
var total = totalCharacters;
//var total = 10;
var promises = [];

for(var i = 0; i < total; i++) {
  var promise = $.get('http://gateway.marvel.com:80/v1/public/characters?limit=1&offset=' + offset + '&' +  apiKey)
  .then(function(result) {
    var character = result.data.results[0];
    console.log(character.id);

    if (!character.thumbnail || !character.thumbnail.path || character.thumbnail.path.indexOf(imageNotAvailable) > -1) {
        idsOfCharsWithoutImage.push(character.id);
    }
  });

  promises.push(promise);
  offset = i;
}

Promise.all(promises).then(function() {
  console.log('all done');
  console.info('chars without image: ' + idsOfCharsWithoutImage.length);
  console.info(idsOfCharsWithoutImage);
})