# C 程序：检查给定的整数是正还是负

> 译文： [https://beginnersbook.com/2015/02/c-program-to-check-whether-the-given-integer-is-positive-or-negative/](https://beginnersbook.com/2015/02/c-program-to-check-whether-the-given-integer-is-positive-or-negative/)

在下面的程序中，我们检查输入整数是正数还是负数。如果输入数字大于零，则其为正数，否则为负数。如果数字为零则既不是正数也不是负数。我们在下面的 C 程序中遵循了相同的逻辑。

```c
/* Description: A program to check whether the input
 * integer number is positive or negative. 
 * Written by: Chaitanya Singh
 * Published on: beginnersbook.com
 */
#include <stdio.h>

void main()
{
    int num;

    printf("Enter a number: \n");
    scanf("%d", &num);
    if (num > 0)
        printf("%d is a positive number \n", num);
    else if (num < 0)
        printf("%d is a negative number \n", num);
    else
        printf("0 is neither positive nor negative");
}
```

输出 1：

```c
Enter a number:
0
0 is neither positive nor negative
```

输出 2：

```c
Enter a number:
-3
-3 is a negative number
```

输出 3：

```c
Enter a number:
100
100 is a positive number
```