Data types in C++ can be classified into three major categories :
User-defined data type
Built-in data type
Derived data type
1. User-defined data type : I C++, User-defined data types are Structure, Union, Class and enum etc.
Structure : Structures are used for grouping together elements with dissimilar types. It is often required to group logically related data items together. It has the following syntax :
struct name
{
data type member1;
data type member2;
..............
}
Union : Unions are conceptually similar to structures, it allows us to group together dissimilar type elements inside a single unit. In unions, the same memory space is used for representing different member elements. As a result, union members can only be manipulated exclusive of each other. It has the following syntax :
union name
{
data type member1;
data type member2;
..............
}
Class : In C++, Class is a user-defined data type which is used to declare variables.
Enum : An enumerated data type is also a user-defined data type which provides a way for attaching names to numbers, it increasing comprehensibility of the code. The enum keyword is used to assign those enumerate values. Example :
