--- website: https://www.json.org obj: format extension: "json" mime: "application/json" --- # JSON JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate. It is often used for exchanging data between a web server and a web application, as well as between different programming languages. JSON is commonly used in web development to transfer data between a web server and a web application. For example, when a web application makes a request to a web server, the server might respond with a JSON object or array containing the requested data. Some technologies have been built on top of JSON like [JWT](../internet/JWT.md), [JSONPatch](../tools/JSONPatch.md) or [JSON Schema](../tools/JSON%20Schema.md). ## JSON Syntax JSON is built on two structures: objects and arrays. An object is an unordered set of key/value pairs, while an array is an ordered collection of values. Here is an example of a JSON object: ```json { "name": "John", "age": 30, "city": "New York" } ``` In this example, "name", "age", and "city" are keys, and "John", 30, and "New York" are values. The keys and values are separated by a colon, and each key/value pair is separated by a comma. The entire object is enclosed in curly braces. Here is an example of a JSON array: ```json [ "apple", "banana", "orange" ] ``` In this example, "apple", "banana", and "orange" are values. The values are separated by commas, and the entire array is enclosed in square brackets.