Looping through arrays is easy:

var images = [
  {
    src: '/zero.png',
    title: 'Zero'
  },
  {
    src: '/one.png',
    title: 'One'
  },
  {
    src: '/two.png',
    title: 'Two'
  }
];

images.forEach(function(element, index, array) {
  console.log(index, element);
});

But what if you have an object like this which really looks like it should have been an array?

var images = {
  '0': {
    src: '/zero.png',
    title: 'Zero'
  },
  '1': {
    src: '/one.png',
    title: 'One'
  },
  '2': {
    src: '/two.png',
    title: 'Two'
  }
};

Easy too, just different:

for (var key in images) {
  // skip loop if the property is from prototype
  if (images.hasOwnProperty(key) === false) continue;
  console.log(key, images[key]);
}