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What are Data types?

Data types are used to define the variables that the same of type data it can store in memory. The data types determine the type of data to be stored in memory. The data types are used to represent the different values to be stored in the variable. The variable is a name that refers the memory location which means whenever you create a variable you reserve the space in the memory and based on the data type of the variable the operating system allocates the memory.

For example :

int a;

a= 5; // value of variable

int a;

a= 5; // value of variable

So, in the above example the variable name is ‘a’ and the data type assigned to this variable is integer which means the variable ‘a’ can store only the integer values.

Types of Data types

In C++ the data types are divided into two types.

Primitive Data types :

The primitive data types are built-in data types or you can say predefined data types and they can be used by user to declare variables.

The primitive data types are :

Integer
Character
Floating Point
Double Floating Point
Boolean
Void

Let us discuss these data types briefly.

Integer

For the integer data type ‘int’ keyword is used. This data type requires 4 bytes of memory space and it ranges from the minimum value is -2,147,483,648 and the maximum value is 2,147,483,647, both the values are inclusive.

Let us have a look at the example :

#include <iostream>
using namespace std;
 
int main ()
 
{ 
 
int x, y, res;
 
x = 10;
 
y = 20;
 
res = x + 1;
 
res = x - y;
 
cout << res;
 
return 0;
 
}

#include <iostream>

using namespace std;

int main ()

{

int x, y, res;

x = 10;

y = 20;

res = x + 1;

res = x - y;

cout << res;

return 0;

}

Character

The character data type is used to store characters or a single character. For character data type ‘char’ keyword is used. This data type requires 1 byte of memory space and it ranges from -128 to 127 or 0 to 255.

Let us have a look at the example :

#include<iostream>
using namespace std;

int main()

{


char ch='a';

cout<<"\nCharacter entered is: "<<ch;

return 0;

}

#include<iostream>

using namespace std;

int main()

{

char ch='a';

cout<<"\nCharacter entered is: "<<ch;

return 0;

}

Floating Point

This data type is used for storing single precision floating point values or decimal values. For floating point data type ‘float’ keyword is used. This data type requires 4 byte memory space.

Let us have a look at the example :

#include<iostream.h>#include<conio.h>void main(){ clrscr(); float fl; cout<<“\n\nEnter a floating-point number: “; cin>>fl;getch();}

Double Floating Point

This double floating point data type is used to store double precision floating point values or decimal values. For double floating point data type ‘double’ keyword is used. This data type requires 8 byte of memory space.

Let us have a look at the example :

#include <iostream>
using namespace std;
int main()

{

double a = 400.00;

cout << "The double precision floating point is:"<<a;

return 0;

}

#include <iostream>

using namespace std;

int main()

{

double a = 400.00;

cout << "The double precision floating point is:"<<a;

return 0;

}

Boolean

This data type is used for storing Boolean or logical values. The Boolean variable can store either true or false value. For this data type ‘bool’ keyword is used.

Let us have a look at the example :

#include<iostream>
 using namespace std;
int main()
 
{
 
int x = 10, y = 20, m = 2;
 
bool a, b;
 
a = x == y; // false
 
b = x < y; // true
 
cout << "Value of a is = " << a << "\n";
 
cout << "Value of b is = " << b << "\n";
 
bool c = true;
 
if (c)
 
cout << "Yes" << "\n";
 
else
 
cout << "No" << "\n";
 
int z = false + 5 * m - c;
 
cout << z;
 
return 0;
 
}

#include<iostream>

using namespace std;

int main()

{

int x = 10, y = 20, m = 2;

bool a, b;

a = x == y; // false

b = x < y; // true

cout << "Value of a is = " << a << "\n";

cout << "Value of b is = " << b << "\n";

bool c = true;

if (c)

cout << "Yes" << "\n";

else

cout << "No" << "\n";

int z = false + 5 * m - c;

cout << z;

return 0;

}

Void

The void data type refer the set of empty values. This data type is used with those function which does not returns a value.

Let us have a look at the example :

#include<iostream.h>#include<conio.h>void main(){ clrscr(); float fl; cout<<“\n\nEnter a floating-point number: “; cin>>fl;getch();}

What are data type modifiers?

The data type modifiers are used with built-in data types to modify the length of data which a particular data type can hold.

Some of the data type modifiers available in C++ are :

Signed
Unsigned
Short
Long

With integer base data types you can use signed, unsigned, long and short modifiers. And with char you can use signed and unsigned whereas with double data type you can use long. The signed and unsigned modifiers can also be used as prefix to long or short modifiers.

Data Type / Size(in bytes)	Range
short int / 2	-32,768 to 32,767
unsigned short int / 2	0 to 65,535
unsigned int / 4	0 to 4,294,967,295
int / 4	-2,147,483,648 to 2,147,483,647
long int / 4	-2,147,483,648 to 2,147,483,647
unsigned long int / 4	0 to 4,294,967,295
signed char / 1	-128 to 127
unsigned char / 1	0 to 255
float / 4
double / 8
long double / 12
wchar_t / 2 or 4	1 wide character

Let us have a look at the example :

#include <iostream>
using namespace std; 
int main() 
{

cout << "The size of char : " << sizeof(char);

cout << "\nThe size of int : " << sizeof(int);

cout << "\nThe size of short int : " << sizeof(short int);

cout << "\nThe size of long int : " << sizeof(long int);

cout << "\nThe size of float : " << sizeof(float);

cout << "\nThe size of double : " << sizeof(double);

cout << "\nThe size of wchar_t : " << sizeof(wchar_t);

return 0; 
}

#include <iostream>

using namespace std;

int main()

{

cout << "The size of char : " << sizeof(char);

cout << "\nThe size of int : " << sizeof(int);

cout << "\nThe size of short int : " << sizeof(short int);

cout << "\nThe size of long int : " << sizeof(long int);

cout << "\nThe size of float : " << sizeof(float);

cout << "\nThe size of double : " << sizeof(double);

cout << "\nThe size of wchar_t : " << sizeof(wchar_t);

return 0;

}

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