mongo-db
  1. mongo-db-floor-operator

$floor Operator - (MongoDB Misc)

The $floor operator in MongoDB rounds a specified number down to the nearest integer. It returns the rounded number as a double.

Syntax

The $floor expression has the following syntax:

{ $floor: <number> }

The <number> can be any valid expression that resolves to a number.

Example

Consider the following MongoDB documents.

{ "_id": 1, "amount": 68.64 }
{ "_id": 2, "amount": 23.1 }
{ "_id": 3, "amount": 19.99 }

Using the $floor operator we can round the amount field down to the nearest integer as shown below:

db.collection.aggregate([
   {
      $project: {
         roundedAmount: { $floor: "$amount" }
      }
   }
])

The above query will produce the following output:

{ "_id": 1, "roundedAmount": 68 }
{ "_id": 2, "roundedAmount": 23 }
{ "_id": 3, "roundedAmount": 19 }

Output

The output generated using $floor operator returns the rounded number as a double.

Explanation

The $floor operator is used to round a given number down to the nearest integer. The operator always returns a floating-point number, even if the input number is an integer.

Use

The $floor operator is most commonly used in aggregation pipelines. It can be used to perform complex calculations involving rounding off fractions, which is useful in financial applications.

Important Points

  • The $floor operator rounds a given number down to the nearest integer.
  • The operator always returns a double value, even if the input number is an integer.
  • The $floor operator is most commonly used in aggregation pipelines.

Summary

In this page, we discussed the $floor operator in MongoDB. We covered its syntax, example, output, explanation, use, and important points. The $floor operator is commonly used in financial applications where rounding is necessary to calculate interest, payments, and other values.

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