Question

The program is ignoring Stop when amt is 0 until after 10 numbers have been entered. The program also doesn’t stop after 10 numbers have been entered. Where is my error?

main() {
int amt;
int tot = 0; /* running total */
int i = 0;   /* counts number of times in loop */
while (amt!=0 || i < 10)
    {
     printf("Enter a number (enter 0 to stop): ");
     scanf("%d", &amt);
     tot = tot + amt;
     i++;
    }
printf("The sum of those %d number is %d.\n", i, tot);

}

Answer 1

Your test is happening before amt is assigned. Thus its results are undefined. This test should be moved to the end of the iteration, i.e. a do/while. Whilst you could assign amt to some non-zero value this feels slightly untidy to me.

And surely you mean to use logical AND rather than logical OR? You only want to continue iterating if both amt is non-zero AND i<10.

Of course, if you did move the test to the end of the iteration then you would have to account for the fact that i had been incremented inside the loop.