/TypeScript/Mongo count elements in array

Mongo count elements in array

> db.mycollection.insert({'foo':[1,2,3,4]})
> db.mycollection.insert({'foo':[5,6,7]})

> db.mycollection.aggregate([{$project: { count: { $size:"$foo" }}}])
{ "_id" : ObjectId("5314b5c360477752b449eedf"), "count" : 4 }
{ "_id" : ObjectId("5314b5c860477752b449eee0"), "count" : 3 }

Source: stackoverflow.com

Mongo count elements in array

{ $size: <expression> }

Source: docs.mongodb.com

Mongodb count array size

db.inventory.aggregate([
   {
      $project: {
         item: 1,
         numberOfColors: { $cond: { if: { $isArray: "$colors" }, then: { $size: "$colors" }, else: "NA"} }
      }
   }
] )

Source: docs.mongodb.com

Similar codes

0 vote143 views1 answer
Url prod
TypeScript
0 vote145 views1 answer
Communication between components in angular
TypeScript
-1 vote158 views1 answer
Create database if not exists mysql true spring boot
TypeScript
0 vote183 views1 answer
Element of an array is the same as any of the previous elements pandas
TypeScript
3 votes156 views1 answer
Ts reverse array
TypeScript
0 vote137 views1 answer
Indexable type in ts
TypeScript
0 vote146 views1 answer
Formgroup reset values
TypeScript
22 votes146 views3 answers
Typescript remove an item from array
TypeScript
9 votes184 views2 answers
Open and append to file python if exists if not create
TypeScript
0 vote130 views1 answer
Does casting have a higher precedence than dots java
TypeScript