How to create multiple collection using loop?

Hii all , iam working on monogcxx in qt creator . i need to create multiple collection in a loop.
for example
i have data of rotation in collection “Rotation”. But i need to Rotation2 , 3 , 4 etc upto n ,
so how to create like that . i know programming logic but dont know mongocxx syntax
error happening when we put string variable in
what is the correct syntax???

Hi. Have you tried db.getCollection(str)? You can use variables for collection names this way.