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wdliming

hello!guys,recent days ,i come across a problem when i write a C program,that is "How to calculate the size of struct ",i have a part of C source code below:

Code:

 #include <stdio.h>
 struct b 
{
    float f;    
    int a[2];
    char p;
};

  int main(void)
{
    printf("sizeof(struct(b))=%d\n",sizeof(struct b));
    return 0;
}

After compiling using GCC 4.6.1,the result is
sizeof(struct(b))=16
then ...
I think the
= (sizeof(float)) + 2*(sizeof(int)) + (sizeof(char))
=4+2*4+1
=4+8+1
=13 not equal 16.

oh my god !!
Could some one tell me why?thank you very much! ^@^
(compile environment Windows XP sp3,TDM-GCC 4.6.1,X86 architecture)

wdliming Go4Expert Member
15Mar2012,17:19
	hello!guys,recent days ,i come across a problem when i write a C program,that is "How to calculate the size of struct ",i have a part of C source code below: Code: #include <stdio.h> struct b { float f; int a[2]; char p; }; int main(void) { printf("sizeof(struct(b))=%d\n",sizeof(struct b)); return 0; } After compiling using GCC 4.6.1,the result is sizeof(struct(b))=16 then ... I think the = (sizeof(float)) + 2(sizeof(int)) + (sizeof(char)) =4+24+1 =4+8+1 =13 not equal 16. oh my god !! Could some one tell me why?thank you very much! ^@^ (compile environment Windows XP sp3,TDM-GCC 4.6.1,X86 architecture) Last edited by wdliming; 15Mar2012 at 17:30..