This is the c programming questions and answers section on "Pointers" with explanation for various interview, competitive examination and entrance test. Solved examples with detailed answer description, explanation are given and it would be easy to understand.
1. What is the output of this C code?
int main()
{
char *p = NULL;
char *q = 0;
if (p)
printf(
" p ");
else
printf(
"nullp");
if (q)
printf(
"q\n");
else
printf(
" nullq\n");
}
- A. nullp nullq
- B. Depends on the compiler
- C. x nullq where x can be p or nullp depending on the value of NULL
- D. p q
Answer: Option A
Explanation:
None.
2. What is the output of this C code?
int main()
{
int i = 10;
void *p = &i;
printf(
"%d\n", (int)*p);
return 0;
}
- A. Compile time error
- B. Segmentation fault/runtime crash
- C. 10
- D. Undefined behaviour
Answer: Option A
Explanation:
None.
3. What is the output of this C code?
int main()
{
int i = 10;
void *p = &i;
printf(
"%f\n", *(float*)p);
return 0;
}
- A. Compile time error
- B. Undefined behaviour
- C. 10
- D. 0.000000
Answer: Option D
Explanation:
None.
4. What is the output of this C code?
int *f();
int main()
{
int *p = f();
printf(
"%d\n", *p);
}
int *f()
{
int *j = (
int*)malloc(sizeof(
int));
*j = 10;
return j;
}
- A. 10
- B. Compile time error
- C. Segmentation fault/runtime crash since pointer to local variable is returned
- D. Undefined behaviour
Answer: Option A
Explanation:
None.
5. What is the output of this C code?
int *f();
int main()
{
int *p = f();
printf(
"%d\n", *p);
}
int *f()
{
int j = 10;
return &j;
}
- A. 10
- B. Compile time error
- C. Segmentation fault/runtime crash
- D. Undefined behaviour
Answer: Option A
Explanation:
None.
