Iterating over a collection with access to the index in Ember

each-with-index-in-ember.md

Iterating over a collection with access to the index in Ember

// within your view/component
collectionWithIndices: function () {
  return this.get('collection').map(function (item, idx) {
    item.index = String(idx); // we need 0 to be "0" or Handlebars will consider it falsy
    return item;
  });
}.property('collection.@each'),

{{!-- your template --}}
{{#each thing in collectionWithIndices}}
 index: {{thing.index}}
{{/each}}