Trailing commas have only been allowed in Javascript object literals since ECMAScript 5 in 2009 — JSON dates from 2001. Re comments, Crockford said: "I removed

Trailing commas have only been allowed in Javascript object literals since ECMAScript 5 in 2009 — JSON dates from 2001. Re comments, Crockford said: "I removed comments from JSON because I saw people were using them to hold parsing directives, a practice which would have destroyed interoperability." See: https://archive.ph/20150704102718/https://plus.google.com/+DouglasCrockfordEsq/posts/RK8qyGVaGSr https://archive.ph/20150704102718/https://plus.google.com/+D...