/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 vote144 views1 answer
Edit lights in a room alexa
TypeScript
1 vote248 views2 answers
Ngfor ionic example
TypeScript
7 votes141 views3 answers
How to find how many commits i have done
TypeScript
-80 votes134 views10 answers
Code
TypeScript
4 votes136 views2 answers
Cannot find module .svg' or its corresponding type declarations.
TypeScript
0 vote140 views1 answer
Pytest tests in subfolder
TypeScript
8 votes171 views3 answers
Angular window scroll to top not working
TypeScript
7 votes139 views3 answers
Typescript ignore
TypeScript
14 votes141 views3 answers
Df.value_counts to dataframe
TypeScript
-1 vote168 views1 answer
Type char typescript
TypeScript