json.indexOf

json.indexOf() Function

• Introduced in version 1.3b53

Returns the index of the first occurrence of a value in the JSON Array. If the value does not exist in the JSON Array then -1 is returned. All JSON Array indexes start at 0.

Usage

json.indexOf(array, value)

json.indexOf(array, value, start)

Parameters

• array - The JSON Array to search.
• value - The value to find the index of in the JSON Array.
• start - The index to start searching from, if not specified it defaults to 0.

Examples

Find the index of the first occurrence of 1:

[r: json.indexOf("[1,2,3,1,1,3]", 1)]

Returns: 0

Find the index of the first occurrence of 1, starting at index 1:

[r: json.indexOf("[1,2,3,1,1,3]", 1, 1)]

Returns: 3

Find the index of the first occurrence of 2, starting at index 2:

[r: json.indexOf("[1,2,3,1,1,3]", 2, 2)]

Returns: -1

Finding JSON Objects in an Array. You can also find the indexes of a JSON object in a JSON array.
In this example, json.path.read gets the object with the unique key currency set to Gold in an array of JSON objects representing money. Note that json.get is used because json.path.read always returns the object in an array.
The currency key is presupposed to be unique for every record in this example:

[h: moneyJSON = '[
	{"currency":"Copper", "amount":9},
	{"currency":"Silver", "amount":14},
	{"currency":"Gold", "amount":5}
	]']
[h: justGold = json.get(json.path.read(moneyJSON, "[?(@.currency == 'Gold')]"), 0)]
[r: json.indexOf(moneyJSON, justGold)]

Returns: 2

See Also

json.count()