C Sizeof Operator

The C Sizeof operator is one of the C Programming Operator. It is mostly used to find the array size, structure size and do some calculations as per the results.

The C sizeof operator returns the size (number of bytes) of a declared variable or data type. Let us see one C programming example for better understanding

C Sizeof Operator Example

In this sizeof example program, We are going to check the size of an integer, float, character, double and character array using sizeof operator.

/* C Sizeof Operator Example */

#include <stdio.h>

int main()
{
  int a;
  int b[20];
 
  printf(" Size of int data type:%d \n ", sizeof (int) );
  printf(" Size of char data type:%d \n ", sizeof (char) );
  printf(" Size of float data type:%d \n ", sizeof (float) );
  printf(" Size of double data type:%d \n ", sizeof (double) );

  printf(" Size of int data type:%d \n ", sizeof (a) ); 
  printf(" Size of an int array:%d \n ", sizeof (b) );
  
  return 0;
}

OUTPUT

The result of sizeof (b): Although, we declared the size of the b as 20 it display output as 80. Because b array will store 20 integer members, and every integer member needs 4 bytes of space ( means 20 * 4 Bytes for every integer member.)