The C and C++Programming Language

Data Types in C++

These are the  7  C++ Data Types −

Data Types can be modified using the following keywords −

• signed
• unsigned
• short
• long

The following table shows the variable type, how much memory it takes to store the value in memory, and what is maximum and minimum value which can be stored in such type of variables.

Size of variables can change on the basis of compilers.

Program to display size of data types

#include <iostream>

using namespace std;

int main() {
cout << "Size of char : " << sizeof(char) <<"\n";
cout << "Size of int : " << sizeof(int) << "\n";
cout << "Size of short int : " << sizeof(short int) <<"\n";
cout << "Size of long int : " << sizeof(long int) << "\n";
cout << "Size of float : " << sizeof(float) << "\n";
cout << "Size of double : " << sizeof(double) << "\n";
cout << "Size of wchar_t : " << sizeof(wchar_t) << "\n";

return 0;
}

Output

The above program can be also made using variables.

#include <iostream>

using namespace std;

int main() {
char ch;
int i;
short int s;
long int l;
float f;
double d;
wchar_t w;
cout << "Size of char : " << sizeof(ch) <<"\n";
cout << "Size of int : " << sizeof(i) << "\n";
cout << "Size of short int : " << sizeof(s) <<"\n";
cout << "Size of long int : " << sizeof(l) << "\n";
cout << "Size of float : " << sizeof(f) << "\n";
cout << "Size of double : " << sizeof(d) << "\n";
cout << "Size of wchar_t : " << sizeof(w) << "\n";

return 0;
}

Read the program below and try to interpret the output.

#include <iostream>

using namespace std;

int main() {

short int si=32767;
unsigned short int ui=32767;

cout << "Value of signed int : " << si << "\n";
cout << "Value of unsigned int : " << ui <<"\n";
si++;
ui++;
cout << "Value of signed int : " << si << "\n";
cout << "Value of unsigned int : " << ui <<"\n";
si=10;
ui=10;
cout << "Value of signed int : " << si << "\n";
cout << "Value of unsigned int : " << ui <<"\n";
si=si+ 65536;
ui=ui+ 65536;
cout << "Value of signed int : " << si << "\n";
cout << "Value of unsigned int : " << ui <<"\n";
return 0;
}

&amp;nbsp;

Macros that give the ranges of Data Types are stored in limits.h

// C++ code to demonstrate the macros for data types
#include<iostream>
#include<limits.h> // for int,char macros
#include<float.h> // for float,double macros
using namespace std;
int main()
{

// Displaying ranges with the help of macros
cout << "char ranges from : " << CHAR_MIN << " to " << CHAR_MAX;
cout << "\n\nshort char ranges from : " << SCHAR_MIN << " to " << SCHAR_MAX;
cout << "\n\nunsigned char ranges from : " << 0 << " to " << UCHAR_MAX;

cout << "\n\n\nshort int ranges from : " << SHRT_MIN << " to " << SHRT_MAX;
cout << "\n\nunsigned short int ranges from : " << 0 << " to " << USHRT_MAX;
cout << "\n\nint ranges from : " << INT_MIN << " to " << INT_MAX;
cout << "\n\nunsigned int ranges from : " << 0 << " to " << UINT_MAX;
cout << "\n\nlong int ranges from : " << LONG_MIN << " to " << LONG_MAX;
cout << "\n\nunsigned long int ranges from : " << 0 << " to " << ULONG_MAX;
cout << "\n\nlong long int ranges from : " << LLONG_MIN << " to " << LLONG_MAX;
cout << "\n\nunsigned long long int ranges from : " << 0 << " to " << ULLONG_MAX;

cout << "\n\n\nfloat ranges from : " << FLT_MIN << " to " << FLT_MAX;
cout << "\n\nnegative float ranges from : " << -FLT_MIN << " to " << -FLT_MAX;
cout << "\n\ndouble ranges from : " << DBL_MIN << " to " << DBL_MAX;
cout << "\n\nnegative double ranges from : " << -DBL_MIN << " to " << +DBL_MAX;

return 0;

}

Let us try some programs with float and double.

#include <iostream>
#include<limits.h> // for int,char macros
#include<float.h> // for float,double macros
using namespace std;

int main() {

float f=FLT_MAX;
double d=DBL_MAX;

cout << "Value of float : " << f << "\n";
cout << "Value of double : " << d <<"\n";

f=f+f;
d=d+d;
cout << "Value of float : " << f << "\n";
cout << "Value of double : " << d <<"\n";

return 0;
//return 0;
}

end