Dynamic Memory Management MCQ Quiz

Which call correctly allocates space for 50 integers?

• int *p = malloc(50);

• int *p = malloc(50 * sizeof(int));

• int *p = calloc(sizeof(int), 50);

• Both B and C

Compared to malloc, calloc additionally:

• Aligns memory

• Initializes memory to zero

• Allocates on the stack

• Guarantees contiguous physical pages

In a typical C program, how do the heap and stack grow in memory?

• Both grow upwards

• Both grow downwards

• Stack grows downward, heap grows upward

• Stack grows upward, heap grows downward

What is a key difference between stack and heap memory allocation?

• Stack is slower but dynamic; heap is faster and fixed

• Stack is manual; heap is automatic

• Stack is automatically managed; heap requires manual management

• Heap variables are cleared on function exit

Which statement creates a pointer to a structure and allocates memory dynamically?

• struct item *p = malloc(sizeof(struct item));

• struct item p = malloc(sizeof(item));

• item *p = new item;

• struct item p; *p = malloc(sizeof(p));

Which is valid?

• free(&x); where int x;

• free(p); where p points to malloced memory

• free(p+1); where p points to malloced memory

• free((void*)0x1234);

realloc(p, 0) does:

• Always equivalent to free(p) and returns NULL

• Keeps memory unchanged

• Undefined behavior

• Returns pointer to a zero-sized usable block

Which is a double free?

• free(p); p = NULL; free(p);

• free(p); free(p);

• free(NULL);

• p = realloc(p, 0); free(p);

What does calloc(k, s) guarantee that malloc(k*s) does not?

• Same address every call

• Zero-initialized memory

• Faster allocation

• Thread safety

Which of the following memory areas does malloc() allocate memory from?

• Stack

• Heap

• Static Memory

• Code Segment