<C Primer Plus>5 Looping while

 1 #include <stdio.h>
 2 int main(void){
 3     long num;
 4     long sum = 0L;
 5     int status;
 6 
 7     printf("Please input an integer to be summed.");
 8     printf("(q to quit): ");
 9     status = scanf("%ld", &num);
10     while (status == 1){
11         sum = sum + num;
12         printf("Pleast enter next integer (q to quit):");
13         status = scanf("%ld", &num);
14     }
15     printf("Those integers sum to %ld.\n", sum);
16 
17     return 0;
18 }
The pseudocode:

　　initialize sum to 0
　　prompt user
　　read input
　　while the input is an integer
　　　　　　add the input to sum
　　　　　　promt user
　　　　　　then read the next input

　　after input completes ,print sum

 1 #include <stdio.h>
 2 int main(void){
 3     long num;
 4     long sum = 0L;
 5 
 6     printf("Please input an integer to be summed.");
 7     printf("(q to quit): ");
 8     while (1 == scanf("%ld", &num) ){
 9         sum += num;
10         printf("Pleast enter next integer (q to quit):");
11     }
12     printf("Those integers sum to %ld.\n", sum);
13 
14     return 0;
15 }

The pseudocode :
while getting and testing the value succeeds
　　process the value