How to return a JSON response from a controller

dmitrii_fediuk (Dmitrii Fediuk) March 18, 2016, 2:17pm 3

See also:

How is the «Content-Type» HTTP Header added to a JSON response?
The \Magento\Framework\App\Response\Http::representJson() does not specifies a JSON response’s charset and removes a previously specified charset, so not-latin characters are rendered incorrectly by all the modern browsers