Data Types in C++

In C++, variables are essential for storing information, and their data types determine the kind of information they can hold as well as the memory they require. Let's explore the basic data types, type modifiers, and how to use them in Dev-C++ with examples.

 

Primitive Built-in Types

C++ offers a rich set of built-in data types. Here are the basic ones:

1. Boolean (bool): Used to store true or false values.
2. Character (char): Used to store single characters.
3. Wide Character (wchar_t): Used to store wide characters, often for Unicode.
4. Integer (int): Used to store whole numbers.
5. Floating Point (float): Used to store single-precision floating-point numbers.
6. Double Floating Point (double): Used to store double-precision floating-point numbers.
7. Void (void): Represents the absence of type.

These types can be modified using type modifiers such as signed, unsigned, short, and long.

 

Type Modifiers

Type modifiers expand the range of data types:

• signed: Can store negative and positive values.
• unsigned: Can only store positive values.
• short: Uses less memory.
• long: Uses more memory.

 

Memory and Range

Different data types consume different amounts of memory and have different ranges. Here’s a table summarizing this:

Type	Typical Bit Width	Typical 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	-2147483648 to 2147483647
unsigned int	4 bytes	0 to 4294967295
short int	2 bytes	-32768 to 32767
unsigned short int	2 bytes	0 to 65535
long int	8 bytes	-9223372036854775808 to 9223372036854775807
unsigned long int	8 bytes	0 to 18446744073709551615
long long int	8 bytes	-(2^63) to (2^63)-1
unsigned long long int	8 bytes	0 to 18446744073709551615
float	4 bytes	Varies
double	8 bytes	Varies
long double	12 bytes	Varies
wchar_t	2 or 4 bytes	1 wide character

 

Example in Dev-C++

To find out the size of various data types on your system using Dev-C++, you can use the following program:

#include <iostream>

using namespace std;

 

int main() {

    cout << "Size of bool : " << sizeof(bool) << " byte(s)" << endl;

    cout << "Size of char : " << sizeof(char) << " byte(s)" << endl;

    cout << "Size of int : " << sizeof(int) << " byte(s)" << endl;

    cout << "Size of short int : " << sizeof(short int) << " byte(s)" << endl;

    cout << "Size of long int : " << sizeof(long int) << " byte(s)" << endl;

    cout << "Size of float : " << sizeof(float) << " byte(s)" << endl;

    cout << "Size of double : " << sizeof(double) << " byte(s)" << endl;

    cout << "Size of wchar_t : " << sizeof(wchar_t) << " byte(s)" << endl;

 

    return 0;

}

  

Checking Value Limits

To find the minimum and maximum values of various data types, you can use the numeric_limits library:

#include <iostream>

#include <limits>

using namespace std;

 

int main() {

    cout << "Int Min: " << numeric_limits<int>::min() << endl;

    cout << "Int Max: " << numeric_limits<int>::max() << endl;

    cout << "Unsigned Int Min: " << numeric_limits<unsigned int>::min() << endl;

    cout << "Unsigned Int Max: " << numeric_limits<unsigned int>::max() << endl;

    cout << "Long Int Min: " << numeric_limits<long int>::min() << endl;

    cout << "Long Int Max: " << numeric_limits<long int>::max() << endl;

    cout << "Unsigned Long Int Min: " << numeric_limits<unsigned long int>::min() << endl;

    cout << "Unsigned Long Int Max: " << numeric_limits<unsigned long int>::max() << endl;

 

    return 0;

}

 

Typedef Declarations

You can use typedef to create new names for existing types:

typedef int feet;

feet distance;

 

Enumerated Types

Enumerations allow you to define a type with a set of named values:

#include <iostream>

using namespace std;

 

enum Color { red, green, blue };

Color c = blue;

 

int main() {

    cout << "Color value: " << c << endl;  // Outputs: 2 (default value for blue)

    return 0;

}

In summary, understanding variables and data types in C++ is crucial for effective programming. Dev-C++ can be used to experiment with these concepts, providing a practical way to see how different types and their modifiers behave on your system.