1. #define SECONDS_PER_YEAR (60 * 60 * 24 * 365)UL

2. 三重条件操作符这个操作符存在C语言中的原因是它使得编译器能产生比if-then-else更优化的代码，了解这个用法是很重要的。

3. #error

4. 怎么样用C编写死循环呢？

while(1){}

for(;;){}

Loop:
...
goto Loop;

5.

• a) int a; // An integer
• b) int *a; // A pointer to an integer
• c) int **a; // A pointer to a pointer to an integer
• d) int a[10]; // An array of 10 integers
• e) int *a[10]; // An array of 10 pointers to integers
• f) int (*a)[10]; // A pointer to an array of 10 integers
• g) int (*a)(int); // A pointer to a function a that takes an integer argument and returns an integer
• h) int (*a[10])(int); // An array of 10 pointers to functions that take an integer argument and return an integer

6.

• const int a;
• int const a;
• const int *a;
• int * const a;
• int const * a const;

7.

int square(volatile int *ptr)
{
   int a,b;
   a = *ptr;
   b = *ptr;
   return a * b;
}

8.

#define BIT3 (0x1<<3) 
static int a; 
void set_bit3(void) 
{ 
    a |= BIT3; 
} 

void clear_bit3(void) 
{
    a &= ~BIT3; 
}

9.

int *ptr; 
ptr = (int *)0x67a9; 
*ptr = 0xaa55; 

*(int * const)(0x67a9) = 0xaa55;

10.

__interrupt double compute_area (double radius) 
{ 
    double area = PI * radius * radius; 
    printf(" Area = %f", area); 
    return area; 
} 

有多少错误？

11.

void foo(void) 
{ 
    unsigned int a = 6; 
    int b = -20; 
   (a+b > 6) ?puts("> 6") : puts("<= 6"); 
}

12.

if ((ptr = (char *)malloc(0)) == NULL) 
    puts("Got a null pointer"); 
else 
    puts("Got a valid pointer");

未经允许不得转载：TacuLee » 你的嵌入式软件的功力如何？