Can comments be used in JSON?

Question

Can I use comments inside a JSON file? If so, how?

Answer 1

NO. JSON used to support comments, but they were abused and removed from the standard.

From the creator of JSON:

I removed comments from JSON because I saw people were using them to hold parsing directives, a practice which would have destroyed interoperability. I know that the lack of comments makes some people sad, but it shouldn't. - Douglas Crockford, 2012

The official JSON site is at JSON.org. JSON is defined as a standard by ECMA International. There is always a petition process to have standards revised. It is unlikely that annotations will be added to the JSON standard for several reasons.

JSON by design is an easily reverse-engineered (human parsed) alternative to XML. It is simplified even to the point that annotations are unnecessary. It is not even a markup language. The goal is stability and interoperablilty.

Anyone who understands the "has-a" relationship of object orientation can understand any JSON structure - that is the whole point. It is just a directed acyclic graph (DAG) with node tags (key/value pairs), which is a near universal data structure.

This only annotation required might be "//These are DAG tags". The key names can be as informative as required, allowing arbitrary semantic arity.

Any platform can parse JSON with just a few lines of code. XML requires complex OO libraries that are not viable on many platforms.

Annotations would just make JSON make less interoperable. There is simply nothing else to add, unless what you really need is a markup language (XML), and don't care if your persisted data is easily parsed.

BUT as the creator of JSON also observed, there has always been JS pipeline support for comments:

Go ahead and insert all the comments you like. Then pipe it through JSMin before handing it to your JSON parser. - Douglas Crockford, 2012