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mongosh Method

This page documents a mongosh method. This is not the documentation for a language-specific driver, such as Node.js.

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 method has the following parameter:

A function to apply to each document visited by the cursor. returns a Cursor object. Note that .map() only converts the type, it does not create a new cursor. You can convert the Cursor object to an Array with .toArray().

These examples refer to the products collection:

{ _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 }

Get the product names.

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

Calculate a discounted sale price and return the results as an array.

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

Confirm that the output is an Array


See also:

cursor.forEach() for similar functionality.

← cursor.limit()

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