hey. when I use (ans!='d') the printf("sum\n") prints the line twice and then the getchar() function is beeing used.
on the other hand when I use (ans=='d') then the second ans= getchar() function doesn't work. the program just ends.Code:#include <stdio.h> main() { char ans; ans= getchar(); while(ans!='d') { printf("sum\n"); ans= getchar(); } }
what am I not doing correct?
dh
>main()
is the correct definition of main without arguments.Code:int main ( void )
>char ans;
Despite the name, getchar actually returns an int so that it can properly handle EOF.
>what am I not doing correct?
I don't know. What input are you giving the program and what did you expect to happen?
My best code is written with the delete key.
what I like to do is to have one user input. and if that user input is the condition used with the while loop the loop should be run else not. then when the loop is almost finished (in the end of the loop) have another user input to ask to repeat the same thing (the same loop)
(the example program is just to make it simple)
So you basicly want somthing like this:
That may not ne what you want, but its along the same linesCode:printf("Enter a number: "); scanf("%d", &num); while ( num != 100 ) { printf("No, give me a ton: "); scanf("%d", &num); }
Double Helix STL
hope this will solve the problemCode:#include <stdio.h> void clear_buffer(void) { int ch; while((ch=getchar()) != '\n' && ch != EOF); } int main() { int ans; while((ans=getchar()) != 'd') { printf("sum\n"); clear_buffer(); } getchar(); return 0; }
sshaish2005
hi,
you got to understand one thing here, getchar accepts a character from the standard input device .i.e. keyboard, when u press a character it is stored in 'ans' first, then you press enter key which is also a character again.
This is what lets your program print the statement twice, to rectify this you need not change your whole program like other people suggested, but just add a line in your present program saying ' fflush(stdin); ' immediately after the getchar() line.
This will solve your problem.
Why fflush(stdin) is wrongprogram saying ' fflush(stdin);
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
Hi vart,
I mean the program should be something like this
Vart, actually fflush() refreshs the buffer so, the problem will not persist.Code:void main() { char ans; ans=getchar(); fflush(stdin); while (ans!='d') { printf("sum\n"); ans=getchar(); fflush(stdin); } }
Am I wrong Vart?
}
on some systems it will work, on some - will not...
so - the FAQ provides a portable way to fflush input stream:
FAQ > How do I... (Level 2) > Flush the input buffer
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
hey all. thank you for many replies.
SWGH: your answer works using an int variable, but not using a char variable
ssharish2005 and vart: your answers works just fine. thank you
dh
