C++ Data Types
C++ is rich in its data types. Data types specifies a particular kind of data item defined by the values it can take. Data types in C++ can be classified into the following:
- Built-in Data Types
- User Defined Data Types
- Derived Data Types
Built-in Data Types
C++ supports various built-in data types. They are given below in the table:
| Type | Storage size | Value range |
|---|---|---|
| char | 1 byte | -128 to 127 or 0 to 255 |
| unsigned char | 1 byte | 0 to 255 |
| signed char | 1 byte | -128 to 127 |
| int | 4 bytes | -2,147,483,648 to 2,147,483,647 |
| unsigned int | 4 bytes | 0 to 4,294,967,295 |
| signed int | 4 bytes | -2147483648 to 2147483647 |
| short int | 2 bytes | -32768 to 32767 |
| unsigned short int | 2 bytes | 0 to 65,535 |
| signed short int | 2 bytes | -32768 to 32767 |
| long int | 8 bytes | -2,147,483,648 to 2,147,483,647 |
| unsigned long int | 8 bytes | 0 to 4,294,967,295 |
| signed long int | 8 bytes | -2,147,483,648 to 2,147,483,647 |
| float | 4 bytes | 3.4E-38 to 3.4E+38 |
| double | 8 bytes | 1.7E-308 to 1.7E+308 |
| long double | 10 bytes | 3.4E-4932 to 1.1E+4932 |
Another built-in data type is void. Two uses of void are to specify the return type of a function when it is not returning any value and to indicate an empty argument list to a function.
User Defined Data Types
There are three types of user defined data types.
| Data Types | Description |
|---|---|
| Structures and class | We described struct as user-defined data type in C. These data type also legal in C++, some more features have been added to make them suitable for object oriented programming. C++ also permits to define another user-defined data type known as class. It can be used any other basic data type to declare variables. The class variables are known as objects which are the main focus of the object-oriented programming. |
| Enumerated | Enumeration is another user-defined data type which provides a way for attaching names to number. The enum keyword automatically enumerates a list of words by assigning them values 0,1,2 and so on. This facility provides an alternative means for creating symbolic constants. |
Derived Data Types
There are three types of derived data types in C++.
| Data Types | Description |
|---|---|
| Arrays | An array is used for storing a collection of data. Arrays in C++ is similar to C. The only exception is the way character arrays are initialized. |
| Functions | Functions have undergone major changes in C++. While some of these changes are simple others require a new way of thinking when organizing a program. |
| Pointers | Pointers are used to access the memory and deal with their addresses. |