ARRAY_ENUMERATE

This function takes an array of arbitrary type as input, and produces an integer array of the same length containing increasing numbers. The returned array starts with value one. Every successive element is incremented by one, it holds that array[i] = array[i - 1] + 1.

NULLs contained in the parameter array are treated like any other value, and result in a non-null element in the returned array.

If the parameter array is NULL, then the function also returns NULL.

Syntax

ARRAY_ENUMERATE(<array>)

Parameters

Parameter	Description	Supported input types
<array>	The array to be enumerated. The length of the returned array is the same as the length of the parameter array.	Any array type.

Return Type

ARRAY(INT)

Example

The following example returns an array with values one to four:

SELECT ARRAY_ENUMERATE([7, 9, 3, 4]) AS one_to_four;

Returns: [1, 2, 3, 4]

The array passed to the function can contain arbitrary types:

SELECT ARRAY_ENUMERATE(['hello', 'world']) AS one_to_two;

Returns: [1, 2]

NULL values are still reflected in the returned result:

SELECT ARRAY_ENUMERATE([7, NULL, 3, NULL]) AS one_to_four;

Returns: [1, 2, 3, 4]

The function also works with nested arrays, but only the length of the outer array is taken into account:

SELECT ARRAY_ENUMERATE([[ 7, NULL ], NULL, [ 1, 2 ]]) AS one_to_three;

Returns: [1, 2, 3]

If the array passed to the function is NULL, so is the result:

SELECT ARRAY_ENUMERATE(NULL) AS null_result;

Returns: NULL