我正在从一本书中学习C,我开始使用循环指令.但是有一个我无法理解的示例代码.
谁能告诉我作者为何使用过status = scanf("%ld", &num);？为什么有一个=用scanf？
/* summing.c -- sums integers entered interactively */
#include <stdio.h>
int main(void)
{
long num;
long sum = 0L; /* initialize sum to zero */
int status;
printf("Please enter an integer to be summed ");
printf("(q to quit): ");
status = scanf("%ld", &num);
while (status == 1) /* == means "is equal to" */
{
sum = sum + num;
printf("Please enter next integer (q to quit): ");
status …我正在从一本书中学习C,作者正在解释使用1表示真,0表示使用while循环.他用以下示例代码解释但我无法理解.
INPUT
#include<stdio.h>
int main(void)
{
int n = 3;
while (n)
printf("%2d is true\n", n--);
printf("%2d is false\n", n);
n = -3;
while (n)
printf("%2d is true\n", n++);
printf("%2d is false\n", n);
getchar();
return 0;
}
OUTPUT
3 is true
2 is true
1 is true
0 is false
-3 is true
-2 is true
-1 is true
0 is false