- Reference >
- Operators >
- Aggregation Pipeline Operators >
- Boolean Aggregation Operators
Boolean Aggregation Operators¶
Boolean expressions evaluate their argument expressions as booleans and return a boolean as the result.
In addition to the false
boolean value, Boolean expression evaluates as
false
the following: null
, 0
, and undefined
values. The
Boolean expression evaluates all other values as true
, including non-zero
numeric values and arrays.
Name | Description |
---|---|
$and |
Returns true only when all its expressions evaluate to
true . Accepts any number of argument expressions. |
$or |
Returns true when any of its expressions evaluates to true .
Accepts any number of argument expressions. |
$not |
Returns the boolean value that is the opposite of its argument expression. Accepts a single argument expression. |