StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POWhy scanf("%c\n") have a delay in stdin
primarykey
Id
18167255
data
AcceptedAnswerId
18167308
AnswerCount
6
ClosedDate
CommentCount
2
CommunityOwnedDate
CreationDate
2013-08-10T23:23:00.127
FavoriteCount
0
LastActivityDate
2013-08-11T06:55:53.950
LastEditDate
LastEditorUserId
0
OwnerUserId
2595939
ParentId
0
PostTypeId
1
Score
1
ViewCount
615
LastEditorDisplayName
text
Body
Well , I know there are lots of question about <code>scanf</code>, but I still want to ask. I hope someone can explain the rules or principle for this issue: code first: <pre><code> #include <stdio.h> int main() { int c = 'W'; while(c != 'F'){ scanf("%c",&c); printf("c is : %c\n",c); } return 0; } </code></pre> And here is the output: <pre><code>E c is : E c is : <--newline G c is : G c is : <---newline again W c is : W c is : <---newline F c is : F </code></pre> Well, I still can understand by now, for the newline I input stay in buffer and assignment c every time after alphabet a press.So , I try code2: <pre><code> #include <stdio.h> int main() { int c = 'W'; while(c != 'F'){ scanf("%c\n",&c); //<-- the only modified place. printf("c is : %c\n",c); } return 0; } </code></pre> Then I get this screen: <pre><code>E G <---why the input and has one step before the output? c is : E W c is : G S c is : W C c is : S F c is : C R <---R was left in stdin, turn to a garbage, I didn't hope this. c is : F </code></pre> I also have try to flush the <code>stdin</code> and <code>stdout</code>, still no use. Note : I know if use <code>scanf("%c",c);</code>and another <code>scanf("%c",&d);</code> behind to deal with <code>'\n'</code> can fixed this, I just confuesed ,I hope to understand why the code2's issue happened. I have check the answer before but I am not a really careful man , if this answer is really duplicate ,all downvote can be understand. :) Thanks in advance.
Tags
<c><stdin><scanf>
Title
Why scanf("%c\n") have a delay in stdin
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USLidong Guo
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. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
3. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POWhy scanf("%c\n") have a delay in stdin
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. COyou would probably be better off using simply `scanf("%c ",&c)`, which will skip past any and all trailing whitespace.
 singulars
 PostPostId
 POWhy scanf("%c\n") have a delay in stdin
 UserUserId
 USDave
2. COWhen one uses `\n` at the format end of `scanf()`, its time to consider`fgets()` & `scanf()` instead.
 singulars
 PostPostId
 POWhy scanf("%c\n") have a delay in stdin
 UserUserId
 USchux

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.