Data Types in CPP (C Plus Plus)

By Prof. Fazal Rehman Shamil
Last modified on August 7th, 2021

Data Types in C++

What are Data Types?

All variables/arrays etc use data-type during declaration to restrict the type of data to be stored. Every data type occupies a different amount of memory. 

Commonly Used  C++ Data Types

Variable Type Variable Size in Byte Range
int 4 bytes -2147483648 to 2147483647
float 4 bytes +/- 3.4e +/- 38 (~7 digits)
double 8 bytes +/- 1.7e +/- 308 (~15 digits)
char 1 byte -127 to 127 or 0 to 255

Rarely Used  C++ Data Types

Variable Type Variable Size in Byte Range
unsigned int 4 bytes 0 to 4294967295
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 4 bytes -2,147,483,648 to 2,147,483,647
signed long int 4 bytes same as long int
unsigned long int 4 bytes 0 to 4,294,967,295
long double 8 bytes +/- 1.7e +/- 308 (~15 digits)
wchar_t 2 or 4 bytes 1 wide character
unsigned char 1 byte 0 to 255
signed char 1 byte -127 to 127

 


The size of the variables might be different from those shown in the above table, depending on the PC and the PC you are using. Following is the example, which will produce the correct size of various data types on your system. we can use
sizeof(data type) for finding size in coding.

Output

Size of int = 4

Size of char = 1

Size of float = 4
Size of double = 8

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