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
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W3Schools
w3schools.com โ€บ js โ€บ js_json_arrays.asp
JSON Arrays
Arrays in JSON are almost the same as arrays in JavaScript.
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JSON Schema
json-schema.org โ€บ understanding-json-schema โ€บ reference โ€บ 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.
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JSON for Modern C++
json.nlohmann.me โ€บ api โ€บ basic_json โ€บ 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'; }
Find elsewhere
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Processing
processing.org โ€บ reference โ€บ 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 โ€ฆ
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Oracle
docs.oracle.com โ€บ en โ€บ database โ€บ oracle โ€บ oracle-database โ€บ 26 โ€บ sqlrf โ€บ JSON_ARRAY.html
JSON_ARRAY
3 weeks ago - It converts each expression to a JSON value, and returns a JSON array that contains those JSON values.
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GeeksforGeeks
geeksforgeeks.org โ€บ javascript โ€บ 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.
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Oracle
docs.oracle.com โ€บ javaee โ€บ 7 โ€บ api โ€บ javax โ€บ json โ€บ 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.
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MySQL
dev.mysql.com โ€บ doc โ€บ refman โ€บ 8.4 โ€บ en โ€บ 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.
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RestfulAPI
restfulapi.net โ€บ home โ€บ json โ€บ 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.
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IBM
ibm.com โ€บ docs โ€บ en โ€บ db2 โ€บ 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.
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Tutorialspoint
tutorialspoint.com โ€บ sql โ€บ 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.
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Reddit
reddit.com โ€บ r/learnjavascript โ€บ 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.
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JAXB
javaee.github.io โ€บ tutorial โ€บ 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.
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Leapcell
leapcell.io โ€บ blog โ€บ understanding-json-arrays-a-practical-guide
Understanding JSON Arrays: A Practical Guide | Leapcell
July 25, 2025 - JSON (JavaScript Object Notation) ... generate. One of its fundamental structures is the array, which is widely used to represent ordered collections of data....