This version of the documentation is archived and no longer supported.

Array Aggregation Operators


For details on specific operator, including syntax and examples, click on the specific operator to go to its reference page.

Name Description
$arrayElemAt Returns the element at the specified array index.
$concatArrays Concatenates arrays to return the concatenated array.
$filter Selects a subset of the array to return an array with only the elements that match the filter condition.
$isArray Determines if the operand is an array. Returns a boolean.
$size Returns the number of elements in the array. Accepts a single expression as argument.
$slice Returns a subset of an array.