Data Types:

The data type defines a set of values and a set of operation on those values. The computer manipulates various types of data. This data is given to the computer as input. The data is processed according to the program instructions to produce outputs. As the computer memory is organized in bytes, and the memory for each variable is associated with its data type.

The data that is entered or the information and its data type are defined before designing the actual program that is used to process the data. The type of each data value is identified at the beginning of program design.

C program may need to process different types of data. Each data type require amount of memory. C++ programming language provides the following data types:

Data Type Purpose
int Stores numeric values
float Stores real values
double Stores large real values
char Stores character values
bool Stores either true or false
void It is value less. Void means “nothing”

 

Categories of Data types

C++ programming language provides the following ways to use data types:

  • Standard data types/built in data types
  • User defined data types

Standard Data types

A data type that is predefined in the language is called standard data type or built in data type. Some examples of standard data type are int, float, long, bool and char etc.

 

User defined data types

The C++ programming language also allows the user to define his own data types and they are called user defined data types.

 

Integer Data type

Integer data is the numeric value with no decimal point or fraction. It includes both positive and negative values. The minus sign – is used to indicate the negative value. If no sign is used, the value is considered to be positive by default.

EXAPLES

Some of examples of integer type data are 15, -2, etc.

 

Types of integer data

The C++ programming language provides different types of integer data. These are as follows:

  1. Int (it is used to store whole number values)
  2. Short int (it takes two bytes in memory)
  3. unsigned int (it stores only positive integer values)
  4. long int (it stores larger values)
  5. Unsigned long int (it is used to store larger positive values)
Data type Size in Bytes Ranges
int 2 -32768 to 32767
short 2 -32768 to 32767
Unsigned int 2 0 to 65535
long 4 -2147483648 to 2147483647
Unsigned long 4 0 to 4294967295

 

Floating point data type

This type of data is a numeric value with decimal point or fraction. It is also called real type data. It includes both positive and negative values.

EXAMPLES

10.5, -3.4, etc

 

Types of floating point

C++ programming language provides different types of floating point data. These are as follows:

  1. Float
  2. Double
  3. Long double
Data type Size in Bytes Description
float 4 3.4*10^-38 to 3.4*10^38
double 8 1.7*10^-308 to 1.7*10^308
Long double 10 1.7 *10^-4932 to 1.7*10^4932

 

Character data type

This data type is used to store character value. It takes 1 byte in memory. It is used to represent letters, number or punctuation marks and a few other symbols.

These types of values are normally given in single quotes.

EXAMPLE

‘a’, ‘5’, ‘#’, etc

Boolean data type

The bool data type is used to store either true or false.

Void data type

Void data type is used in functions that do not have any return value this will be discussed on later chapters.

Data type of expressions

The data type of an expression depends on the types of operand in the expression. For example the result of an expression is int if both the operands are integer.