$bit
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Definition
-
$bit
-
The
$bit
operator performs a bitwise update of a field. The operator supports bitwiseand
, bitwiseor
, and bitwisexor
(i.e. exclusive or) operations. To specify a$bit
operator expression, use the following prototype:Only use this operator with integer fields (either 32-bit integer or 64-bit integer).
To specify a
<field>
in an embedded document or in an array, use dot notation.Note
All numbers in the
mongo
shell are doubles, not integers. Use theNumberInt()
or theNumberLong()
constructor to specify integers. See NumberInt or NumberLong for more information.
Examples
Bitwise AND
Consider the following document inserted into the collection switches
:
The following update()
operation updates the expdata
field to the result of a bitwise and
operation between the current value NumberInt(13)
(i.e. 1101
) and NumberInt(10)
(i.e. 1010
):
The bitwise and
operation results in the integer 8 (i.e. 1000
):
And the updated document has the following value for expdata
:
The mongo
shell displays NumberInt(8)
as 8
.
Bitwise OR
Consider the following document inserted into the collection switches
:
The following update()
operation updates the expdata
field to the result of a bitwise or
operation between the current value NumberLong(3)
(i.e. 0011
) and NumberInt(5)
(i.e. 0101
):
The bitwise or
operation results in the integer 7 (i.e. 0111
):
And the updated document has the following value for expdata
:
Bitwise XOR
Consider the following document in the collection switches
:
The following update()
operation updates the expdata
field to the result of a bitwise xor
operation between the current value NumberLong(1)
(i.e. 0001
) and NumberInt(5)
(i.e. 0101
):
The bitwise xor
operation results in the integer 4:
And the updated document has the following value for expdata
: