The JSON Array is a native JSON Data Type and supported by many MapTool macro functions as an input or output.
JSON.org defines it like this:
An array is an ordered collection of values. An array begins with
[(left bracket) and ends with
](right bracket). Values are separated by a
An array may hold any of the supported JSON Data Types: Number, String, Object, Array, Boolean and Null.
Examples of JSON Arrays
An array of strings. Note that each name is quoted and the whole array has single quotes around it.
[h: beatles = '["Paul", "John", "George", "Ringo"]']
An array of prime numbers. The numbers should not be quoted but the whole array has quotes around it.
[h: primes = "[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]"]
A better way to initialize an array as you'll be less likely to have issues with quoting.
[h: list = json.append("", "Peter", "Paul", "Mary")]
Access the elements of a JSON array with json.get() or other JSON Functions.
[h: list = json.append("", "Peter", "Paul", "Mary")] [r: json.get(list,2)]