Pointers and Memory Management MCQ Questions

Learn core concepts, essential formulas, and attempt practice questions designed on the latest TCS NQT testing patterns.

Key Concepts & Formulas

1Pointer holds the memory address of a variable.
2'*' operator dereferences pointer (reads value at address).
3'&' operator returns address of variable.
4Pointer size is independent of data type (usually 4 bytes on 32-bit, 8 bytes on 64-bit).

Practice Question 1

What is output of: int a=5; int *p=&a; *p=10; printf("%d", a);

A) 10

B) 5

C) Address of a

D) Error

Correct Answer: A) 10

Step-by-step Solution: p points to a. *p = 10 modifies the value at the address of a, changing a to 10.

Practice Question 2

If double *d is declared on a 64-bit machine, what is sizeof(d)?

A) 8 bytes

B) 4 bytes

C) 16 bytes

D) 1 byte

Correct Answer: A) 8 bytes

Step-by-step Solution: On 64-bit systems, all pointers are 8 bytes, regardless of whether they point to char, int, or double.

A pointer declaration double *p does not allocate a double in memory, just an address storage box.