$bitOr (aggregation)

Definition

$bitOr

Returns the result of a bitwise or operation on an array of int and long values.

Syntax

The $bitOr operator has the following syntax:

{ $bitOr: { [ <expression1>, <expression2>, ... ] }

Behavior

If the operands include both integers and long values, MongoDB sign-extends the calculated integer result and returns a long value. Otherwise, if the operands include only integers or only longs, MongoDB returns results with the corresponding value type.

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 argument is an empty array, the operation returns NumberInt(0).

If any of the arguments in the array equate to null, the operation returns null.

Examples

The examples on this page use the switches collection, which contains the following documents:

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) }
] )

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

  [
    { _id: 0, result: 127 },
    { _id: 1, result: 3 },
    { _id: 2, result: 7 }
  ]

db.switches.aggregate( [
  {
    $project: {
      result: {
        $bitOr: [ "$a", NumberLong("63") ]
      }
    }
  }
])

  [
    { _id: 0, result: Long("0") },
    { _id: 1, result: Long("2") },
    { _id: 2, result: Long("3") }
  ]

Learn More

• Aggregation Operators

• $bit