APTITUDE QUESTION

1) Which operator is used to get the "content of a variable pointed to by a pointer"?

1.Dot Operator (.)

2.Address of Operator (&)

3.Indirection or De-reference Operator (*)

4.Arrow Operator (→)

Answer & Explanation:

Correct answer: 3

Indirection or De-reference Operator (*)

2) What will be the type of a pointer, which is pointing to an integer variable?

1.int *

2.long int *

3.char *

4.unsigned *

Answer & Explanation:

Correct answer: 1

int *

 To store the address of an integer variable, we need to declare an integer pointer (int *).

3) If ptr is a pointer to one dimensional array, which statement will return the value of 3rd element?

1.(ptr+3)

2.*(ptr+3)

3.(&ptr+3)

4.*ptr+3

Answer & Explanation:

Correct answer: 2

*(ptr+3)

 ptr will point to the address of one-dimensional array and * (indirection or de-reference operator) returns the value of variable pointed by a pointer, thus *(ptr+3) will return the value of 3rd element of array.

 4) Consider the given declaration:

int* ptr1,ptr2;

What is the type of ptr2 here?

1.int * (Integer pointer)

2.void

3.void * (void pointer)

4.int (integer)

Answer & Explanation:

Correct answer: 2

int (integer)

 Here, compiler will ignore the pointer asterisk, when carrying a type over to multiple declarations. If we split the declarations of ptr1 and ptr2 into multiple declarations, compiler will consider them like:

 int *ptr1;

int ptr2;

Thus, ptr is not int*, it is int type variable.

5) What will be the correct way to declare two integer pointers using single line declaration?

1.int *ptr1,*ptr2;

2.int* ptr1,ptr2;

3.int * ptr1, ptr2;

4.All of the above

Answer & Explanation:

Correct answer: 1

int *ptr1,*ptr2;

 It is possible to declare multiple pointers in a single line declaration, use asterisk (*) before the pointer names.

6) Consider the following statement:

int arr[5],*ptr;

How to initialize ptr with the address of array arr?

1.ptr = arr;

2.ptr = &arr[0];

3.ptr = &arr;

4.Both 1) and 2)

Answer & Explanation:

Correct answer: 4

Both 1 and 2

 A pointer to an array of integers can be initialized using array name (arr) or base address of first array element .