/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

9 votes178 views6 answers
Angular reload component
TypeScript
1 vote186 views1 answer
Contextual typing in typescript
TypeScript
0 vote170 views1 answer
Spread types may only be created from object types firebase
TypeScript
0 vote176 views1 answer
Copy all elements from one list to another ajav
TypeScript
0 vote184 views1 answer
Mysql workbench an apparmor policy prevents this sender
TypeScript
1 vote169 views1 answer
Nodejs exec exit code
TypeScript
0 vote180 views1 answer
Append scripts using jquery
TypeScript
0 vote184 views1 answer
How to pass data between requests in api
TypeScript
0 vote166 views1 answer
Url prod
TypeScript
0 vote185 views2 answers
How to check if a string contains only alphabets and space in java
TypeScript