User-defined data types

A user-defined data type (UDT) is a data type that derived from an existing data type. You can use UDTs to extend the built-in types already available and create your own customized data types.

There are six user-defined types:

• Structured data types
• Enumerated data types
• Array data types
• Pointer data types
• Class data types
• Union data types

User-defined data types are data types created by the user for a specific application or program. There are several types of user-defined data types, including:

1. Structured data types: Structured data types are user-defined data types that group together variables of different data types under a single name. For example, a struct in C/C++ is a user-defined data type that combines variables of different data types into a single unit.

2. Enumerated data types: Enumerated data types are user-defined data types that allow a programmer to define a set of named values. For example, in C/C++, an enumerated data type can be used to define a set of values for the days of the week.

3. Array data types: An array is a user-defined data type that allows a programmer to group together a fixed number of variables of the same data type under a single name. Arrays are used to store and manipulate collections of data, such as lists or tables.

4. Pointer data types: Pointer data types are user-defined data types that allow a programmer to create variables that store memory addresses. Pointers are used to create dynamic data structures, such as linked lists and trees.

5. Class data types: Class data types are user-defined data types that allow a programmer to encapsulate data and methods into a single unit. Classes are used to create objects in object-oriented programming languages, such as C++ and Java.

6. Union data types: A union is a user-defined data type that allows a programmer to store different types of data in the same memory location. Unions are used to conserve memory and represent multiple data types in a single variable.