Below are two structures defined in C/C++:
struct a
{
static int i;
void fun() {int i;}
};
struct b
{
static int i;
};
a obj1;
b obj2;
why sizeof of both obj1 and obj2 are same?
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Praveen Pandey
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2Why wouldn't they be? They are both empty classes. BTW your class definitions are both missing a trailing `;`. – juanchopanza Sep 22 '15 at 08:28
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`void fun() {int i;}` ist just a declaration of a member function. This takes no space at all. – Jabberwocky Sep 22 '15 at 08:31
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@MichaelWalz It is also *definition*, so it could take space, although not in the class. – juanchopanza Sep 22 '15 at 08:32
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@juanchopanza right, but it doesn't take space anyway, unless we have virtual functions, then we have the firtual function table pointer which takes up 4 or 8 bytes depending on the compiler. – Jabberwocky Sep 22 '15 at 08:33
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@MichaelWalz Code usually takes space. – juanchopanza Sep 22 '15 at 08:37
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2Functions are not stored in the class object. – Galik Sep 22 '15 at 08:51
1 Answers
3
Non-virtual member functions and static members don't affect the size of an object, as they aren't stored inside the object.
Adding one or more virtual member functions would increase the size by an implementation-specific amount, usually the size of a pointer.
molbdnilo
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