abnormal behavior of scanf [duplicate]
I have code as below which scans a matrix, w - width of matrix, h - heigth of matrix.
I am using Visual Studio 2010.
Every time I get a char it increases j by 2 (I put the break point and come to know this behavior).
int w = 0, h = 0;
char map[21][21];
int i,j;
scanf("%d%d", &w, &h);
for(i = 1; i <= h; ++i){
for(j = 1; j <= w; ++j){
//fflush(stdin);
scanf("%c",&map[i][j]);
//fflush(stdin);
}
}
What can be the reason behind this?
at the time of scan i am giving value, w = 7, h = 5.
I don't see any error in my code....Please help me.
The problem is due to '\n'
characters (on pressing Enter ) left behind by scanf
.
One way to eat up these newline character is place a ' '
before %c
in scanf
;
scanf(" %c",&map[i][j]);
^
|
space
Another way is to use a loop to eat up all the \n
by getchar()
int ch;
while((ch=getchar())!='\n' && ch != EOF );
You need to skip trailing newline from previous scanf
Don't use fflush(stdin)
Use:
int c;
while((c=getchar())!='\n' && c != EOF ); //eats newline came from scanf
after scanf
call