How to determine whether a string is valid JSON?

code-snippets, json, jsonlint, php, validation

Solution

If you are using the built in `json_decode` PHP function, `json_last_error` returns the last error (e.g. `JSON_ERROR_SYNTAX` when your string wasn't JSON).

Usually `json_decode` returns `null` anyway.

Problem

Does anyone know of a robust (and bullet proof) is_JSON function snippet for PHP? I (obviously) have a situation where I need to know if a string is JSON or not. Hmm, perhaps run it through a JSONLint request/response, but that seems a bit overkill.

Original source