C++ Data Types

C++ Data Types

While composing a program in any language, you will need to apply several variables to stock all those information. Variables are emptiness but supplied memory locations to stock the values. It means that when you establish a variable you supply some spaces in the memory.

You maybe like to stock the information of various data types like integer, floating points, double floating points, character, wide character, boolean, etc. Depending on the data types of variables, the operating system assigned memory and make decisions about what can be stocked in the supply memory.

 

As explained in the Variables chapter, a variable in C++ must be a specified data type:

 

 

 

 

 

 

Basic Data Types

The data type specifies the size and type of information the variable will store:

 

Data Type	Size	Description
int	4 bytes	Stores whole numbers, without decimals
float	4 bytes	Stores fractional numbers, containing one or more decimals. Sufficient for storing 7 decimal digits
double	8 bytes	Stores fractional numbers, containing one or more decimals. Sufficient for storing 15 decimal digits
boolean	1 byte	Stores true or false values
char	1 byte	Stores a single character/letter/number, or ASCII values

 

Note: ASCII: American Standard Code for Information Interchange

 

Main Categories of C++ Data Types: 

• Numbers
• Booleans
• Characters
• Strings

Primitive Build-it Types

C++ allows the programmer a lot of classification of built-in as well as user-defined data types. The following table lists seven basic data types in C++:

Data Type	Keyword
Boolean	bool
Character	char
Floating point	float
Double floating point	double
Integer	int
Valueless	void
Wide character	wchar_t

Many basic data types of Cplusplus can be modified by using one or more of these type modifiers:

• signed
• unsigned
• short
• long

The table below shows the types of variables, how much that memory takes to store the value in it, and what is the minimum and maximum value that can be stored in such types of variables.

Date Type	Typical Bit Width	Typical Range
char	1byte	-127 to 127 or 0 to 255
unsigned char	1byte	0 to 225
signed char	1byte	-127 to 127
int	4bytes	-2147483648 to 2147483647
unsigned int	4bytes	0 to 4294967295
signed int	4bytes	-2147483648 to 2147483647
short int	2bytes	-32768 to 32767
unsigned short int	Range	0 to 65,535
signed short int	Range	-32768 to 32767
long int	4bytes	-2,147,483,647 to 2,147,483,647
signed long int	4bytes	same as long int
unsigned long int	4bytes	0 to 4,294,967,295
float	4bytes	+/- 3.4e +/- 38 (~7 digits)
double	8bytes	+/- 1.7e +/- 308 (~15 digits)
long double	8bytes	+/- 1.7e +/- 308 (~15 digits)
wchar_t	2 or 4 bytes	1 wide character

The size of the variables may be different from the above table. It's depending on the device or computer you are using.

The following example will produce the correct size of various data types on the computer.

#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;
}

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