该程序从用户那里获取一个数字，并检查该数字是positive还是negative或zero 。
使用……检查正或负
#include
int main() {
double num;
printf("Enter a number: ");
scanf("%lf", &num);
if (num <= 0.0) {
if (num == 0.0)
printf("You entered 0.");
else
printf("You entered a negative number.");
} else
printf("You entered a positive number.");
return 0;
}
您还可以使用嵌套的if else语句解决此问题。
如果…则使用嵌套检查正数或负数
#include
int main() {
double num;
printf("Enter a number: ");
scanf("%lf", &num);
if (num < 0.0)
printf("You entered a negative number.");
else if (num > 0.0)
printf("You entered a positive number.");
else
printf("You entered 0.");
return 0;
}
输出1
Enter a number: 12.3
You entered a positive number.
输出2
Enter a number: 0
You entered 0.