For some reason this while loop executes twice and the strings are printed twice before it prompts for input. I had assumed it was that the input buffer had a character in it, but it does not to my knowledge. Any advice?
while (count >= 0 && stop != 83 && isClosed == 0) {
printf("Percentage of Door Closed: %d\n",count);
count -= 10;
printf("If sensor detects object press 'S'\n");
printf("Press any button to continue closing door\n");
stop = getchar();
if (count == 0) {
isClosed=1;
}
}
Output:
Percentage of Door Closed: 100
If sensor detects object press 'S'
Press any button to continue closing door
Percentage of Door Closed: 90
If sensor detects object press 'S'
Press any button to continue closing door
a
Percentage of Door Closed: 80
If sensor detects object press 'S'
Press any button to continue closing door
Percentage of Door Closed: 70
If sensor detects object press 'S'
Press any button to continue closing door
S
You're picking up the newline character that gets sent to the input stream when you type S <Enter>
. You can deal with this a couple of ways:
while ((stop = getchar()) == '\n'); // loops until it reads a non-newline
// character
or
scanf(" %c", &stop); // note leading blank in format string; this tells scanf
// to skip any leading whitespace characters.
I had a similar problem today, since I didn't use getchar
to get my character and instead used scanf("%c", &stop)
. Once I changed the %c
to %s
for string retrieval it fixed the problem.
I'm not certain but getString
might fix your issue as I think it would do the same thing.
Could be that you're starting the program with a key that also fills the buffer as some keys might generate several characters. Put a breakpoint at stop = getchar() and watch the value of stop when you step over it in the first iteration of the loop.
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