Keys are immutable, therefore, the elements in an unordered_set cannot be modified once in the container - However, they can be inserted and removed. Unordered sets do not allow duplicates and are initialized using comma-delimited values enclosed in curly braces.

Can set have duplicate values in Python?

Every set element is unique (no duplicates) and must be immutable (cannot be changed). However, a set itself is mutable. We can add or remove items from it.

Does set in CPP allow duplicates?

In Set duplicate values are not allowed to get stored. On other hand in case of MultiSet we can store duplicate values. In case of Set, one cannot change the value once it gets inserted however we can delete or insert it again. However in case of MultiSet also we cannot change the value once get inserted.