MongoDB select where in array of _id?

Easy :)

db.collection.find( { _id : { $in : [1,2,3,4] } } );

taken from: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24in

Because mongodb uses bson and for bson is important attribute types. and because _id is ObjectId you must use like this:

db.collection.find( { _id : { $in : [ObjectId('1'),ObjectId('2')] } } );

and in mongodb compass use like this:

{ "_id" : { $in : [ObjectId('1'),ObjectId('2')] } }

Note: objectId in string has 24 length.

In this code list is the array of ids in user collection

var list = ["5883d387971bb840b7399130","5883d389971bb840b7399131","5883d38a971bb840b7399132"]

    .find({ _id: {$in : list}})

You can try this

var ids = ["5883d387971bb840b7399130","5883d389971bb840b7399131","5883d38a971bb840b7399132"];

var oids = [];
ids.forEach(function(item){
oids.push(new ObjectId(item));
});

.find({ _id: {$in : oids}})