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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.