Introduction

The long keyword is also used as a data type in programming languages. Same as other data types, its size also varies from compiler to compiler i.e., the 64-bit compiler would give a size of long as 8 bytes whereas 32-bit compiler gives size as 4 bytes.

Note: The ‘long’ keyword is never used with ‘char’ and ‘float’ data types.

Let’s understand its functioning with the help of a program.

Program

#include<stdio.h>
int main()
{
int x;
long y;
double z;
long int u;
long long v;
long double w;


printf("Size of int variable: %d bytes\n",sizeof(x));
printf("Size of long variable: %d bytes\n",sizeof(y));
printf("Size of double variable: %d bytes\n\n",sizeof(z));
printf("Size of long int variable: %d bytes\n",sizeof(u));
printf("Size of long long variable: %d bytes\n",sizeof(v));
printf("Size of long double variable: %d bytes\n",sizeof(w));
return 0;
}

Output

Explanation

In the above program, firstly we access the size of int, long, and double data types by writing the statements

printf(“Size of int variable: %d bytes\n”,sizeof(a));

printf(“Size of long: %d bytes\n”,sizeof(b));

printf(“Size of double: %d bytes\n\n”,sizeof(c));

and that give 4, 4, 8 respectively as output. Thus, size of long keyword is 4.

printf(“Size of long int: %d bytes\n”,sizeof(d));

While using ‘long’ with other data types we came to know that ‘long int’ is equivalent to ‘long’ and ‘int’ since all three have the same size i.e., 4 bytes.

printf(“Size of long long: %d bytes\n”,sizeof(e)); this statement gives size of ‘long long’ as 8.

printf(“Size of long double: %d bytes\n”,sizeof(f)); this statement gives size of ‘long double’ as 8.

This means that size of ‘long long’ and ‘long double’ is greater than the other data types.