get (Function)
Function returns the value at the specific index, null if index is out of range.
Syntax
<OBJECT|INT|LONG|FLOAT|DOUBLE|BOOL|STRING> list:get(<OBJECT> list, <INT> index)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| list | Attribute containing the list | OBJECT | No | Yes | |
| index | Index of the element | INT | No | Yes |
Example 1
list:get(stockSymbols, 1)
The list:get(stockSymbols, 1) function retrieves the element at index 1 (the second element) in the stockSymbols list. If the index is valid, it returns the value of the element at that position. If the index is out of range, the function returns null.
Example 2
CREATE STREAM InputStream (list OBJECT, index INT);
CREATE SINK STREAM OutputStream (listElement OBJECT);
@info(name = 'ListElementGetter')
INSERT INTO OutputStream
SELECT list:get(list, index) AS listElement
FROM InputStream;
In this stream worker example, a query named ListElementGetter processes events from the InputStream, which contains a list (list) and an index (index). The list:get(list, index) function retrieves the list element at the specified index. If the index is valid, the element value is output as listElement for each event to the OutputStream. If the index is out of range, the function outputs null to listElement.