JSONs

JSONs, or JSON (JavaScript Object Notation), is a widely used text-based format for representing structured data. It originated from JavaScript but is language independent and widely supported by many programming languages. The plural form JSONs is unusual; most references treat JSON as a mass noun referring to the format or to individual documents.

JSON documents encode data as objects and arrays. An object is an unordered collection of name/value pairs, enclosed in curly braces. An array is an ordered list enclosed in square brackets. Values can be strings, numbers, booleans, null, objects, or arrays. Strings are enclosed in double quotes and support Unicode; numbers follow the JSON number syntax. JSON is text and is typically encoded in UTF-8. It does not allow comments in standard form, and trailing commas are invalid.

JSON is defined by ECMA-404 and is closely aligned with RFC 8259. It is commonly used for data interchange in web APIs, configuration files, and logging. Related formats include JSON Lines, a streaming variant where each line is a separate JSON document, and BSON, a binary JSON variant used by some databases.

Validation and structure can be enhanced with schemas, such as JSON Schema, which describe the allowed shapes and types of data. While JSON is easy to parse with libraries across languages, it should be parsed safely and not evaluated as code. Security considerations include validating inputs, handling large payloads to avoid resource exhaustion, and ensuring proper character encoding.