I'll elaborate a bit more on ChrisR awesome answer and bring images from his awesome reference.

A valid JSON always starts with either curly braces { or square brackets [, nothing else.

{ will start an object:

{ "key": value, "another key": value }

Hint: although javascript accepts single quotes ', JSON only takes double ones ".

[ will start an array:

[value, value]

Hint: spaces among elements are always ignored by any JSON parser.

And value is an object, array, string, number, bool or null:

So yeah, ["a", "b"] is a perfectly valid JSON, like you could try on the link Manish pointed.

Here are a few extra valid JSON examples, one per block:

{}

[0]

{"__comment": "json doesn't accept comments and you should not be commenting even in this way", "avoid!": "also, never add more than one key per line, like this"}

[{   "why":null} ]

{
  "not true": [0, false],
  "true": true,
  "not null": [0, 1, false, true, {
    "obj": null
  }, "a string"]
}
Answer from cregox on Stack Overflow
🌐
W3Schools
w3schools.com › js › js_json_arrays.asp
JSON Arrays
Arrays in JSON are almost the same as arrays in JavaScript.
Discussions

How to write a simple array in json?
I have an array var array_list=["apple","orange","cat","dog"]; How do i write this in json? I saw tutorials in w3schools but it showed that json has name value/pairs,should we always write it i... More on stackoverflow.com
🌐 stackoverflow.com
Can a JSON file start with an array instead of an object?
Any valid JSON primitive is also a valid top-level JSON object. A JSON file could just as easily contain a single string, or even a single floating-point number, and still be valid. More on reddit.com
🌐 r/learnprogramming
18
11
May 25, 2024
Problems in understand top-level-JSON-array
I'm reading a doc mention top-level-JSON-array. It is pretty difficult for me to understand about its name, the essence of the code and why it is… More on reddit.com
🌐 r/learnjavascript
5
5
October 3, 2017
Hi guys, how do I loop through an array in json, and put values in another array using logstash?
You might want to try doing a ruby code section for this More on reddit.com
🌐 r/elasticsearch
3
1
April 13, 2020
🌐
JSON Schema
json-schema.org › understanding-json-schema › reference › array
JSON Schema - array
In Python, "array" is analogous to the list or tuple type, depending on usage. However, the json module in the Python standard library will always use Python lists to represent JSON arrays.
🌐
Processing
processing.org › reference › jsonarray
JSONArray / Reference / Processing.org
A JSONArray stores an array of JSON objects. JSONArrays can be generated from scratch, dynamically, or using data from an existing file. JSON can also be output and saved to disk, as in …
Find elsewhere
🌐
Oracle
docs.oracle.com › en › database › oracle › oracle-database › 26 › sqlrf › JSON_ARRAY.html
JSON_ARRAY
2 weeks ago - It converts each expression to a JSON value, and returns a JSON array that contains those JSON values.
🌐
GeeksforGeeks
geeksforgeeks.org › javascript › what-is-json-array
What is JSON Array? - GeeksforGeeks
July 23, 2025 - For example, the array below has 6 string elements, "Ram", "Shyam", "Radhika", "Akshay", "Prashant" and "Varun", each element is separated with a comma (,). ["Ram", "Shyam", "Radhika", "Akshay", "Prashant", "Varun"] Example: Here we will assign a JSON Array of Strings to the key students in the jsonStringArray object.
🌐
JSON for Modern C++
json.nlohmann.me › api › basic_json › array
array - JSON for Modern C++
The following code shows an example for the array function. #include <iostream> #include <nlohmann/json.hpp> using json = nlohmann::json; int main() { // create JSON arrays json j_no_init_list = json::array(); json j_empty_init_list = json::array({}); json j_nonempty_init_list = json::array({1, 2, 3, 4}); json j_list_of_pairs = json::array({ {"one", 1}, {"two", 2} }); // serialize the JSON arrays std::cout << j_no_init_list << '\n'; std::cout << j_empty_init_list << '\n'; std::cout << j_nonempty_init_list << '\n'; std::cout << j_list_of_pairs << '\n'; }
🌐
MySQL
dev.mysql.com › doc › refman › 8.4 › en › json-creation-functions.html
MySQL :: MySQL 8.4 Reference Manual :: 14.17.2 Functions That Create JSON Values
Two aggregate functions generating JSON values are available. JSON_ARRAYAGG() returns a result set as a single JSON array, and JSON_OBJECTAGG() returns a result set as a single JSON object.
🌐
RestfulAPI
restfulapi.net › home › json › json array
JSON Array - Multi-dimensional Array in JSON
November 4, 2023 - JSON Array is a list of items surrounded by square brackets. Each item in the array is separated by a comma. Learn about multi-dimensional arrays.
🌐
IBM
ibm.com › docs › en › db2 › 12.1.x
JSON_ARRAY scalar function
The JSON_ARRAY function generates a JSON array by explicitly listing the array elements by using JSON-expression, or by using a query.
🌐
Oracle
docs.oracle.com › javaee › 7 › api › javax › json › JsonArray.html
JsonArray (Java(TM) EE 7 Specification APIs)
The values in a JsonArray can be of the following types: JsonObject, JsonArray, JsonString, JsonNumber, JsonValue.TRUE, JsonValue.FALSE, and JsonValue.NULL. JsonArray provides various accessor methods to access the values in an array.
🌐
InterSystems
docs.intersystems.com › irislatest › csp › docbook › DocBook.UI.Page.cls
JSON_ARRAY (SQL) | InterSystems SQL Reference | InterSystems IRIS Data Platform 2025.3
JSON_ARRAY takes an expression or (more commonly) a comma-separated list of expressions and returns a JSON array containing those values. JSON_ARRAY can be combined in a SELECT statement with other types of select-items.
🌐
Tutorialspoint
tutorialspoint.com › sql › sql-json-functions-json-array.htm
SQL - JSON_ARRAY() Function
The SQL JSON_ARRAY() function takes an expression or a comma-separated list of expressions and returns a JSON array containing those values. Several types of select-items may be used in conjunction with JSON ARRAY in a SELECT statement.
🌐
Reddit
reddit.com › r/learnjavascript › problems in understand top-level-json-array
r/learnjavascript on Reddit: Problems in understand top-level-JSON-array
October 3, 2017 - It's just an array definition in JSON. It's at the top level, as in the entire JSON object is an array, rather than key value pairs.
🌐
JAXB
javaee.github.io › tutorial › jsonp001.html
Introduction to JSON
JSON defines only two data structures: objects and arrays. An object is a set of name-value pairs, and an array is a list of values.