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How to find size of structure without using sizeof operator in C?

+2 votes
How to find size of structure without using sizeof operator in C?
posted Jun 2, 2015 by Mohammed Hussain

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2 Answers

+2 votes
Best answer

Evaluate Size of Structure Without using Sizeof Operator.

Sizeof operator is used to evaluate the size of any data type or any variable in c programming. Using sizeof operator is straight forward way of calculating size but following program will explain you how to calculate size of structure without using sizeof operator.


  int num1,num2;
  char s1;
  int *ptr;
  int abc[5];

void main()
  int start,last;
  start = &a[1].num1;
  last = &a[0].num1;
  printf("\nSize of Structure : %d Bytes",start-last);

Output :

Size of Structure : 17 Bytes
answer Jun 2, 2015 by Shivaranjini
+1 vote
#include <stdio.h>
typedef  struct
   int a;
   int b;

int main()
   str x;
   str *ptr  = &x;

   printf("%u", (char*)(ptr+1) - (char*)ptr);

   return 0;

Output = 8

answer Jun 7, 2015 by Vikram Singh
Similar Questions
+2 votes

How can I wwap value two variables without using third variable or +/- operator?

+4 votes
printf ("%s %d %f\n", (*ptr+i).a, (*ptr+i).b, (*ptr+i).c);
[Error] invalid operands to binary + (have 'struct name' and 'int')

where ptr is a pointer to the structure and allocated dynamic memory using malloc. Any suggestion would be helpful.

Thanks in advance.