cursor.map()

cursor.map(function)

Important

mongosh Method

This is a mongosh method. This is not the documentation for Node.js or other programming language specific driver methods.

In most cases, mongosh methods work the same way as the legacy mongo shell methods. However, some legacy methods are unavailable in mongosh.

For the legacy mongo shell documentation, refer to the documentation for the corresponding MongoDB Server release:

• mongo shell v4.4

• mongo shell v4.2

• mongo shell v4.0

For MongoDB API drivers, refer to the language specific MongoDB driver documentation.

Applies a function to each document visited by the cursor and collects the return values from successive applications of the function into a Cursor object.

The cursor.map() method has the following parameter:

Parameter	Type	Description
function	function	A function to apply to each document visited by the cursor.

db.products.insertMany([
   { _id: 1, name: 'widget', price: 10.89 },
   { _id: 2, name: 'thing', price: 11.24 },
   { _id: 3, name: 'moppet', price: 8 },
   { _id: 4, name: 'cosa', price: 24.19 }
])

db.products.find().map( function(p) { return p.name; } ) ;

var salePrices = db.products.find().map( function(p) { return p.price * .9 } ).toArray() ;

salePrices.constructor.name