JSON Array

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 , (comma).

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)]

Returns: Mary