Datatype Modifiers in C++

In C++ language Data Type Modifiers are keywords used to change the properties of current properties of data type. Datatype modifiers are classified into following types.
  • long
  • short
  • unsigned
  • signed
Modifiers are prefixed with basic data types to modify (either increase or decrease) the amount of storage space allocated to a variable.
For example, storage space for int data type is 4 byte for 32 bit processor. We can increase the range by using long int which is 8 byte. We can decrease the range by using short int which is 2 byte.


This can be used to increased size of the current data type to 2 more bytes, which can be applied on int or double data types. For example int occupy 2 byte of memory if we use long with integer variable then it occupy 4 byte of memory.


long a;  --> by default which represent long int.


In general int data type occupies different memory spaces for a different operating system; to allocate fixed memory space short keyword can be used.


short int a; --> occupies 2 bytes of memory space in every operating system.


This keyword can be used to make the accepting values of a data type is positive data type.


unsigned int a =100; // right
unsigned int a=-100; // wrong


This keyword accepts both negative or positive value and this is default properties or data type modifiers for every data type.


int a=10; // right
int a=-10; // right
signed int a=10; // right
signed int a=-10;`  // right
Note: in real time no need to write signed keyword explicitly for any data type.