StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
5336381
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2011-03-17T08:01:41.563
FavoriteCount
0
LastActivityDate
2011-03-17T08:16:44.140
LastEditDate
2011-03-17T08:16:44.140
LastEditorUserId
435800
OwnerUserId
435800
ParentId
5336010
PostTypeId
2
Score
3
ViewCount
0
LastEditorDisplayName
text
Body
<code>.size()</code> can return anything, depends on how it is implemented. Anyway, <code>.size()</code> usually returns the size of an container, in other words - the number of elements, that the container contains. The <code>sizeof</code> operator is integrated operator, that returns the number of bytes, allocated on the stack. For example <pre><code> char a[50]; char* b = new char[50]; cout &lt&lt sizeof( a ) &lt&lt '\n'; cout &lt&lt sizeof( b ); </code></pre> prints 50 (which is <code>50 * sizeof( char ) = 50 * 1 = 50</code> ), and the second line prints 8 - as this is the size of the pointer (my machine is x64, that's why it's 8, if I had 32bit CPU, it would be 4). <code>cout << sizeof( *b );</code> would print 1, as <code>*b</code> dereferences the pointer and returns the first element of the array (it's the same as <code>sizeof( b[0] )</code> which is <code>sizeof( char )</code> ) In other words, you'd better rely on <code>.size()</code> if you want to see the number of elements, if it's a container and if it provides such method, of course. <hr> Other example: <pre><code>class A { int a; char b[100]; }; class B { int a; char* b; public: B() { b = new char[100]; } ~B() { delete[] b; } }; int main() { cout &lt&lt sizeof( A ) &lt&lt '\n'; cout &lt&lt sizeof( B ) &lt&lt '\n'; B b; cout &lt&lt sizeof( b ) &lt&lt '\n'; return 0; }</code></pre> The first one, on a x64 plarform, will print 104, as we have <code>100*sizeof(char) + sizeof(int) (=4 )</code> (note <code>104 mod 8 == 0</code>, you'll see why ); The second one and the third one will print the same. But note, we have alignment here! On x64, the alignment is on 8B, so <code>sizeof( char * )</code> gives 8, <code>sizeof( int )</code> gives 4 and this makes 12. BUT <code>12 mod 8 == 4</code> which is != 0, so because of the alignment, <code>sizeof( B )</code> prints 16 ( 16 mod 8 == 0 ). So, when you use <code>sizeof</code>, be very careful.. Hope that helps (: <hr> For your question about list, take a look at this: <pre><code> list&lt int &gt lint; list&lt char &gt lchar; cout &lt&lt sizeof( lint ) &lt&lt '\n'; cout &lt&lt lint.size() &lt&lt '\n'; cout &lt&lt sizeof( lchar ) &lt&lt '\n'; lint.push_back( 10 ); lint.push_back( 10 ); cout &lt&lt lint.size() &lt&lt '\n'; cout &lt&lt sizeof( lint ) &lt&lt '\n'; </code></pre> All operators <code>sizeof</code> will print the same, depends on the implementation of <code>std::list</code>. But the first <code>.size()</code> will return 0, as there're no elements, and the second one will return 2, as we have 2 elements in the list.
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POHow to retrieve size of a data type?
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. USKiril Kirov
UserOwnerUserId
1. USKiril Kirov
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
2. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
3. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.