it enters to endless loop
it doesnt stop for scanf it leaves the old values and enters to an endless loop.
can anybody explain to me please what am i doing wrong????
Code:while(numH>=20||numW>=20||numP>=10||numH<=0||numW<=0||numP<=0){ printf("Incorrect input ,try again\n"); printf("\nEnter puzzle height( < 20 ) width( < 20 ) number of pieces( <= 10 )\n"); scanf("%d %d %d",&numH,&numW,&numP); }
The code works but I think not as you expect it to work.
You have to enter all three values separated by a blank.
if you want to enter them on by one you have to use three scanf statements, or use the this format-string
KurtCode:"%d\n%d\n%d"
http://www.eskimo.com/~scs/C-faq/q12.17.htmlOriginally Posted by ZuK
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
I read that faq-entry but I do not understand it.(guess english is more complicated than I thought )
I tried my format-string and it does what I expect. It behaves strange when I put \n als last char in the format-string.
Kurt
Last edited by ZuK; 09-03-2005 at 02:07 PM.
That's because you don't clear the stream of any errors and then discard the bad input. Naturally scanf() will fail again on the same bad input if you don't get rid of it first:it doesnt stop for scanf it leaves the old values and enters to an endless loop
Code:while(numH>=20||numW>=20||numP>=10||numH<=0||numW<=0||numP<=0){ clearerr(stdin); while ((c = getchar()) != EOF && c != '\n') ; printf("Incorrect input ,try again\n"); printf("\nEnter puzzle height( < 20 ) width( < 20 ) number of pieces( <= 10 )\n"); scanf("%d %d %d",&numH,&numW,&numP); }So don't do that.It behaves strange when I put \n als last char in the format-string.A lot of people get confused with how scanf() deals with whitespace in the format string.
Just because I don't care doesn't mean I don't understand.
I'm pretty sure examples of how to use fgets and sscanf are in the local FAQ...
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
