Question

Point out the correct statement.

(a) $substr ends at a specified index position up to a specified length

(b) $toLower converts a string to lowercase

(c) $gtle returns true if the first value is greater than or equal to the second

(d) All of the mentioned

This question was addressed to me in semester exam.

This intriguing question originated from Pipeline and Sharded Collections topic in section Aggregation Concepts and Aggregation Mechanics of MongoDB

Answer 1

Correct answer is (b) $toLower converts a string to lowercase

Easy explanation: If the argument resolves to null, $toLower returns an empty string “”.