How to get index in Handlebars each helper?

Question

In the newer versions of Handlebars index (or key in the case of object iteration) is provided by default with the standard each helper.

snippet from : https://github.com/wycats/handlebars.js/issues/250#issuecomment-9514811

The index of the current array item has been available for some time now via @index:

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

For object iteration, use @key instead:

{{#each object}}
    {{@key}}: {{this}}
{{/each}}