$bitNot (aggregation)

Definition

$bitNot

Returns the result of a bitwise not operation on a single int or long value.

Syntax

The $bitNot operator has the following syntax:

{ $bitNot: <expression> }

The expression can be a single argument or an array with one int or long element.

Behavior

If any arguments in the array are of a different data type such as a string, double, or decimal, MongoDB returns an error.

If the expression evalutates to null, the operation returns null.

Example

The example on this page uses the switches collection:

db.switches.insertMany( [
    { _id: 0, a: NumberInt(0), b: NumberInt(127) },
    { _id: 1, a: NumberInt(2), b: NumberInt(3) },
    { _id: 2, a: NumberInt(3), b: NumberInt(5) }
] )

The following aggregation uses the $bitNot operator in the $project stage:

db.switches.aggregate( [
  {
    $project: {
      result: {
        $bitNot: "$a"
      }
    }
  }
])

The operation returns the following results:

  [
    { _id: 0, result: -1 },
    { _id: 1, result: -3 },
    { _id: 2, result: -4 }
  ]

Learn More

• Aggregation Operators

• $bit