how to empty a collection in mongodb code example

Example 1: mongodb delete all documents

# To remove all documents in a collection, call the remove method with an empty query
# document {}. The following operation deletes all documents from the bios collection:

db.bios.remove( { } )

Example 2: delete collection mongodb

db.collection.drop()

Example 3: delete an item from db collection mongodb

db.collection.remove(
   <query>,
   {
     justOne: <boolean>,
     writeConcern: <document>
   }
)