Returns the substring of a string. Starts with the character at the specified UTF-8 code point (CP) index (zero-based) in the string and continues for the number of code points specified.
3.4
https://www.mongodb.com/docs/manual/reference/operator/aggregation/substrCP/#mongodb-expression-exp.-substrCP
Returns the substring of a string. Starts with the character at the specified UTF-8 code point (CP) index (zero-based) in the string and continues for the number of code points specified.