C++ Data Types

Data types are the type of data associated with the operation to handle it. The data type tells us about the size and type of the information that a varialbe can store.

Fundamental data types are those which are not composed of any other data types. There are five fundamental data types in C++ :

Data Types	Description	Example
int	Integers are the numbers without any fractional part. The size of int is 4 bytes.	int dt = 10;
float	A number with fractional part known as floating-point number. Sufficient for storing 7 decimal digits. The size of float is 4 bytes.	float dt = 5.75;
double	Double is also used to handle floating-point number. Sufficient for storing 15 decimal digits. The size of double is 8 bytes.	double dt = 14.57;
boolean	Boolean data type is used to stores either true or false values. The size of boolean is 1 byte.	bool dt = true;
char	Character data type is used to store a single character / letter / number, or ASCII values. The size of char is 1 byte.	char dt = 'B';

Data Type Modifiers

The fundamental data types have various modifiers, preceding them. The list of modifiers are:

  signed   unsigned   long   short

Types	Approximate size	Minimal Range
char	1 byte	-127 to 127 or 0 to 255
unsigned char	1 byte	0 to 255
signed char	1 byte	-127 to 127
short int	2 byte	-32768 to 32767
unsigned short int	2 byte	0 to 65,535
signed short int	2 byte	-32768 to 32767
int	4 byte	-2147483648 to 2147483647
unsigned int	4 byte	0 to 4294967295
signed int	4 byte	-2147483648 to 2147483647
long int	4 byte	-2,147,483,648 to 2,147,483,647
signed long int	4 byte	-2,147,483,648 to 2,147,483,647
unsigned long int	4 byte	0 to 4,294,967,295
float	4 byte	+/- 3.4e +/- 38 (~7 digits)
double	8 byte	+/- 1.7e +/- 308 (~15 digits)
long double	8 byte	+/- 1.7e +/- 308 (~15 digits)
wchar_t	2 or 4 byte	1 wide character

Example
The example will show the correct size of the data type.

#include <iostream>
using namespace std;
int main()
{
cout << "Size of char : " << sizeof(char) << endl;
cout << "Size of int : " << sizeof(int) << endl;
cout << "Size of short int : " << sizeof(short int) << endl;
cout << "Size of long int : " << sizeof(long int) << endl;
cout << "Size of float : " << sizeof(float) << endl;
cout << "Size of double : " << sizeof(double) << endl;
cout << "Size of wchar_t : " << sizeof(wchar_t) << endl;
return 0;
}

Output
The ouput of the following code is :

Size of char : 1
Size of int : 4
Size of short int : 2
Size of long int : 4
Size of float : 4
Size of double : 8
Size of wchar_t : 4

Exercise:-

1. What is the size of wchar_t in C++?

A. 2
B. 4
C. 2 or 4
D. based on the number of bits in the system

View Answer

2. Which datatype is used to represent the absence of parameters?

A. Characters
B. Integer
C. Void
D. Float

View Answer

#include <iostream>
using namespace std;
int main()
{
int n;
cout << "Enter an integer: ";
cin >> n;
if ( n % 2 == 0)
cout << n << " is even.";
else
cout << n << " is odd.";
return 0;
}

Enter an integer: 23
23 is odd.