The $replaceOne aggregation pipeline operator was introduced in MongoDB 4.4.
This operator replaces the first instance of a search string in an input string with a replacement string and returns the result.
If the search string isn’t found, then $replaceOne returns the input string.
MongoDB 4.4 introduced the $last aggregation pipeline operator.
This operator returns the last element in an array.
MongoDB 4.4 introduced the $first aggregation pipeline operator.
This operator returns the first element in an array.
In MongoDB, the $arrayElemAt aggregation pipeline operator returns the element at the specified array index.
It accepts two arguments;
From MongoDB 4.4, you can use the $bsonSize aggregation pipeline operator to return the size of a given document in bytes.
$bsonSize accepts any valid expression as long as it resolves to either an object or null.
In MongoDB, you can use the Object.bsonSize() method to return the size of a document in bytes.
From MongoDB 4.4, you can use the $binarySize aggregation pipeline operator to return the size of a given string or binary data value’s content in bytes.
It accepts any valid expression as long as it resolves to either a string or binary data value. The argument can also be null, in which case, $binarySize returns null.
In MongoDB, you can use the $type element query operator to filter a collection of documents based on BSON type. It returns just those documents that have a particular BSON type in a specific field.
You provide the field and the BSON type, and $type will return all documents that match.
In MongoDB, the $type aggregation pipeline operator returns the BSON type of its argument.
You can use it to find out the type of a given field.
From MongoDB 4.0, you can use the $toObjectId aggregation pipeline operator to convert a string to an ObjectId.
The string must be a hexadecimal string of length 24.