Docs Menu

Docs HomeMongoDB Manual

$mod (aggregation)

On this page

  • Definition
  • Example
$mod

Divides one number by another and returns the remainder.

The $mod expression has the following syntax:

{ $mod: [ <expression1>, <expression2> ] }

The first argument is the dividend, and the second argument is the divisor; i.e. first argument is divided by the second argument.

The arguments can be any valid expression as long as they resolve to numbers. For more information on expressions, see Expressions.

Consider a conferencePlanning collection with the following documents:

db.conferencePlanning.insertMany( [
{ "_id" : 1, "city" : "New York", "hours" : 80, "tasks" : 7 },
{ "_id" : 2, "city" : "Singapore", "hours" : 40, "tasks" : 4 }
] )

The following aggregation uses the $mod expression to return the remainder of the hours field divided by the tasks field:

db.conferencePlanning.aggregate(
[
{ $project: { remainder: { $mod: [ "$hours", "$tasks" ] } } }
]
)

The operation returns the following results:

{ "_id" : 1, "remainder" : 3 }
{ "_id" : 2, "remainder" : 0 }
←  $minute (aggregation)$month (aggregation) →

On this page