filter function
Applies to: 
Databricks SQL Databricks Runtime
Filters the array in expr using the function func.
Syntax
filter(expr, func)
Arguments
expr: An ARRAY expression.func: A lambda function.
Returns
The result is of the same type as expr.
The lambda function may use one or two parameters where the first parameter represents the element and the second the index into the array.
Examples
SQL
> SELECT filter(array(1, 2, 3), x -> x % 2 == 1);
[1,3]
> SELECT filter(array(0, 2, 3), (x, i) -> x > i);
[2,3]
> SELECT filter(array(0, null, 2, 3, null), x -> x IS NOT NULL);
[0,2,3]