软件笔试题

软件笔试题

1. How do you code an infinite loop in C?

2. Volatile:

（1）What does the keyword volatile mean? Give an example

（2）Can a parameter be both const and volatile? Give an example

（3）Can a pointer be volatile? Give an example

3. What are the values of a, b, and c after the following instructions:

int a=5, b=7, c;

c = a+++b;

4. What do the following declarations mean?

（1）const int a;

（2）int const a;

（3）const int *a;

（4）int * const a;

（5）int const * a const;

5. Which of the following statements describe the use of the keyword stati

c?

（1）Within the body of a function: A static variable maintains its value

between function revocations

（2）Within a module: A static variable is accessible by all functions wit

hin that module

（3）Within a module: A static function can only be called by other functi

ons within that module

6. Embedded systems always require the user to manipulate bits in register

s or variables. Given an integer variable a, write two code fragments.

The first should set bit 5 of a. The second shnuld clear bit 5 of a. In bo

th cases, the remaining bits should be unmodified.

7. What does the following function return?

char foo(void)

{

unsigned int a = 6;

iht b = -20;

char c;

(a+b > 6) ? (c=1): (c=0);

return c;

}

8. What will be the output of the following C code?

main()

{

int k, num= 30;

k =(num > 5 ? (num <=10 ? 100:200): 500);

printf(“%d”, k);

}

9. What will the following C code do?

int *ptr;

ptr =(int *)Ox67a9;

*ptr = Oxaa55;

10. What will be the output of the follow C code?

#define product(x) (x*x)

main()

{

int i = 3, j, k;

j = product(i++);

k = product(++i);

printf(“%d %d”,j,k);

}

11. Simplify the following Boolean expression

!((i ==12) || (j > 15))

12. How many flip-flop circuits are needed to divide by 16?

13. Provides 3 properties that make an OS, a RTOS?

14. What is pre-emption?