In computer programming, data type is a classification that specifies to compiler or interpreter which type of data user is intending to use.
There are two types of data types –
Primitive/Fundamental data type: Each variable in C/C++ has an associated data type. Each data type requires different amounts of memory and has some specific operations which can be performed over it. Example of fundamental data types –
C++
// C++ program to illustrate
// primitive data types
#include <bits/stdc++.h>
usingnamespacestd;
// main method starts from here
intmain()
{
inta = 2;
floatb = 2.0;
doublec = 2.0003;
chard = 'D';
cout<<"Integer value is = "<< a
<<"\nFloat value is = "<< b
<<"\nDouble value is = "<< c
<<"\nChar value is = "<< d <<endl;
}
// This code has been contributed by cmaggio
Java
// Java program to illustrate
// primitive data types
classGFG {
publicstaticvoidmain(String[] args)
{
// Integer value
inta = 2;
// Float value
floatb = 2.0f;
// Double value
doublec = 2.0003;
// Character
chard = 'D';
System.out.printf("Integer value is = %d", a);
System.out.printf("\nFloat value is = %f", b);
System.out.printf("\nDouble value is = %f", c);
System.out.printf("\nChar value is = %c", d);
}
}
// This code has been contributed by 29AjayKumar
Python
# Python program to illustrate
# primitive data types
# Integer value
a =2
# Float value
b =2.0
# Double value
c =2.0003
# Character
d ='D'
print("Integer value is = ", a);
print("\nFloat value is = ", b);
print("\nDouble value is = ", c);
print("\nChar value is = ", d);
# This code has been contributed by Code_Mech
C#
// C# program to illustrate
// primitive data types
usingSystem;
classGFG {
publicstaticvoidMain()
{
// Integer value
inta = 2;
// Float value
floatb = 2.0f;
// Double value
doublec = 2.0003;
// Character
chard = 'D';
Console.WriteLine("Integer value is = "+ a);
Console.WriteLine("\nFloat value is = "+ b);
Console.WriteLine("\nDouble value is = "+ c);
Console.WriteLine("\nChar value is = "+ d);
}
}
// This code has been contributed by Code_Mech.
PHP
<?php
// PHP program to illustrate
// primitive data types
{
// Integer value
$a= 2;
// Float value
$b= 2.0;
// Double value
$c= 2.0003;
// Character
$d= 'D';
echo("Integer value is = ". $a);
echo("\nFloat value is = ". $b);
echo("\nDouble value is = ". $c);
echo("\nChar value is = ". $d);
}
// This code has been contributed by Code_Mech.
Javascript
<script>
// JavaScript program to illustrate
// primitive data types
// Integer value
vara = 2;
// Float value
varb = 2.0;
// Double value
varc = 2.0003;
// Character
vard = 'D';
document.write("Integer value is = ", a + "<br>");
document.write("\nFloat value is = ", b + "<br>");
document.write("\nDouble value is = ", c + "<br>");
document.write("\nChar value is = ", d + "<br>");
// This code has been contributed by shivanisinghss2110
</script>
Output:
Integer value is = 2
Float value is = 2.000000
Double value is = 2.000300
Char value is = D
Derived data type : These data types are defined by user itself. Like, defining a class in C++ or a structure. These include Arrays, Structures, Class, Union, Enumeration, Pointers etc. Examples of derived data type :
Pointer :
C++
// C++ program to illustrate pointer
// as derived data type
#include <iostream>
usingnamespacestd;
// main method
intmain()
{
// integer variable
intvariable = 10;
// Pointer for storing address
int* pointr;
// Assigning address of variable to pointer
pointr = &variable;
cout << "Value of variable = "<< variable;
// cout << "\nValue at pointer = "<< pointr;
cout << "\nValue at *pointer = "<< *pointr;
return0;
}
// This code is contributed by shubhamsingh10
C
// C program to illustrate pointer
// as derived data type
#include <stdio.h>
// main method starts from here
intmain()
{
// integer variable
intvariable = 10;
// Pointer for storing address
int* pointr;
// Assigning address of variable to pointer
pointr = &variable;
printf("Value of variable = %d", variable);
// printf("\nValue at pointer = %d", pointr);
printf("\nValue at *pointer = %d", *pointr);
return0;
}
Output:
Value of variable = 10
Value at *pointer = 10
Array :
C++
// C++ program to illustrate array
// derived data type
#include <bits/stdc++.h>
usingnamespacestd;
// main method starts from here
intmain()
{
// array of size 5
inta[5] = { 1, 2, 3, 4, 5 };
// indexing variable
inti;
for(i = 0; i < 5; i++)
cout << ("%d ", a[i]);
return0;
}
// This code is contributed by Code_Mech.
C
// C program to illustrate array
// derived data type
#include <stdio.h>
// main method starts from here
intmain()
{
// array of size 5
inta[5] = { 1, 2, 3, 4, 5 };
// indexing variable
inti;
for(i = 0; i < 5; i++)
printf("%d ", a[i]);
return0;
}
Java
// Java program to illustrate array
// derived data type
importjava.util.*;
classGFG {
// Driver code
publicstaticvoidmain(String[] args)
{
// array of size 5
inta[] = { 1, 2, 3, 4, 5};
// indexing variable
inti;
for(i = 0; i < 5; i++)
System.out.printf("%d ", a[i]);
}
}
/* This code contributed by PrinciRaj1992 */
Python3
# Python3 program to illustrate array
# derived data type
# Driver code
# array of size 5
a =[1, 2, 3, 4, 5];
# indexing variable
fori inrange(5):
print(a[i], end =" ");
# This code contributed by mits
C#
// C# program to illustrate array
// derived data type
usingSystem;
classGFG {
// Driver code
publicstaticvoidMain(String[] args)
{
// array of size 5
int[] a = { 1, 2, 3, 4, 5 };
// indexing variable
inti;
for(i = 0; i < 5; i++)
Console.Write("{0} ", a[i]);
}
}
// This code contributed by Rajput-Ji
PHP
<?php
// PHP program to illustrate array
// derived data type
// Driver code
// array of size 5
$a= array(1, 2, 3, 4, 5);
// indexing variable
for($i= 0; $i< 5; $i++)
print($a[$i] . " ");
// This code contributed by mits
?>
Javascript
<script>
// Javascript program to illustrate
// array derived data type
// Array of size 5
let a = [ 1, 2, 3, 4, 5 ];
// Indexing variable
let i;
for(i = 0; i < 5; i++)
document.write(a[i] + " ");
// This code is contributed by decode2207
</script>
Output:
1 2 3 4 5
Structures –
C++
// C++ program to illustrate structure
// derived data type
#include <bits/stdc++.h>
usingnamespacestd;
// structure
structstructure_example
{
intinteger;
floatdecimal;
charcharacter[20];
};
// Main Method
intmain()
{
structstructure_example s = { 15, 98.9, "w3wiki"};
structstructure_example s = { 15, 98.9, "w3wiki"};
printf("Structure data - \n integer = %d \n decimal =
%f \n name = %s", s.integer, s.decimal, s.character);
}
Output:
Structure data -
integer = 15
decimal = 98.900002
name = w3wiki
Fundamental Data Types
Derived Data Types
Fundamental data type is also called primitive data type. These are the basic data types.
Derived data type is the aggregation of fundamental data type.
character, integer, float, and void are fundamental data types.
Pointers, arrays, structures and unions are derived data types.
Character is used for characters. It can be classified as char, Signed char, Unsigned char.
Pointers are used for storing address of variables.
Integer is used for integers( not having decimal digits). It can be classified as signed and unsigned. Further classified as int, short int and long int.
Array is used to contain similar type of data.
float is used for decimal numbers. These are classified as float, double and long double.
structure is used to group items of possibly different types into a single type.
void is used where there is no return value required.
It is like structure but all members in union share the same memory location