Memory Allocation — Part 1 MCQs with Explanations

As it takes two parameters, one is the pointer to the existing block and the second is the value for new size in integers.

stdlib.h is the correct answer to “In C, which header file should be included to use dynamic memory allocation functions”. This question is standard in competitive examination syllabi for Memory Allocation.

To allocate dynamic memory is the correct answer to “What is the purpose of the 'malloc' function in C”. This question is standard in competitive examination syllabi for Memory Allocation.

calloc() is the correct answer to “Which function is used to allocate an array of elements in C”. This question is standard in competitive examination syllabi for Memory Allocation.

Allocates and initializes memory to zero is the correct answer to “What does the 'calloc' function in C do”. This question is standard in competitive examination syllabi for Memory Allocation.

realloc() is the correct answer to “Which function is used to change the size of an allocated block of memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

NULL is the correct answer to “What is the return value of the 'malloc' function if it fails to allocate memory”. This question is standard in competitive examination syllabi for Memory Allocation.

free() is the correct answer to “How do you release dynamically allocated memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

To set memory to zero is the correct answer to “What is the purpose of the 'memset' function in C”. This question is standard in competitive examination syllabi for Memory Allocation.

memcpy() is the correct answer to “Which function is used to copy a block of memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

To deallocate dynamically allocated memory is the correct answer to “What is the purpose of the 'free' function in C”. This question is standard in competitive examination syllabi for Memory Allocation.

Check if the return value is not NULL is the correct answer to “How do you check if the 'malloc' function has successfully allocated memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

sizeofmalloc() is the correct answer to “Which function is used to return the number of bytes allocated by 'malloc'”. This question is standard in competitive examination syllabi for Memory Allocation.

NULL is the correct answer to “What is the return value of the 'realloc' function if it fails to reallocate memory”. This question is standard in competitive examination syllabi for Memory Allocation.

Size of a single element is the correct answer to “What does the 'sizeof' operator in C return for a dynamically allocated array”. This question is standard in competitive examination syllabi for Memory Allocation.

calloc() is the correct answer to “Which function is used to allocate memory for an array of character strings in C”. This question is standard in competitive examination syllabi for Memory Allocation.

An error that occurs when accessing an invalid memory location is the correct answer to “What is a segmentation fault in C”. This question is standard in competitive examination syllabi for Memory Allocation.

Check if the return value is not NULL is the correct answer to “How do you check if the 'realloc' function has successfully reallocated memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

free() is the correct answer to “Which function is used to free allocated memory but does not remove the pointer in C”. This question is standard in competitive examination syllabi for Memory Allocation.

It depends on the system and available memory is the correct answer to “What is the maximum number of bytes that can be allocated using 'malloc' in C”. This question is standard in competitive examination syllabi for Memory Allocation.

'malloc' allocates uninitialized memory, 'calloc' allocates and initializes to zero is the correct answer to “What is the difference between 'malloc' and 'calloc' in C”. This question is standard in competitive examination syllabi for Memory Allocation.

malloc() is the correct answer to “In C, which function is used to allocate memory from the stack”. This question is standard in competitive examination syllabi for Memory Allocation.

It leads to undefined behavior is the correct answer to “What happens if you attempt to free the same block of memory twice in C”. This question is standard in competitive examination syllabi for Memory Allocation.

Flexibility to allocate memory at runtime is the correct answer to “What is the primary advantage of using dynamic memory allocation in C”. This question is standard in competitive examination syllabi for Memory Allocation.

malloc() is the correct answer to “Which function is used to allocate memory for a structure in C”. This question is standard in competitive examination syllabi for Memory Allocation.

'free' is used for dynamic memory, 'delete' is used for static memory is the correct answer to “What is the difference between 'free' and 'delete' in C”. This question is standard in competitive examination syllabi for Memory Allocation.

freeall() is the correct answer to “Which function is used to release all dynamically allocated memory in C”. This question is standard in competitive examination syllabi for Memory Allocation.

To change the size of a previously allocated block of memory is the correct answer to “In C, what is the purpose of the 'realloc' function”. This question is standard in competitive examination syllabi for Memory Allocation.

Unused memory between allocated blocks is the correct answer to “What is a memory fragment in C”. This question is standard in competitive examination syllabi for Memory Allocation.

free() is the correct answer to “With every use of a memory allocation function, what function should be used to release allocated memory, which is no longer needed”. This question is standard in competitive examination syllabi for Memory Allocation.

Binary search is the correct answer to “Array is preferred over linked list for the implementation of . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.

no value is the correct answer to “The free() function frees the memory state pointed to by a pointer and returns . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.

malloc is the correct answer to “When the pointer is NULL, then the function realloc is equivalent to the function . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.

Error is the correct answer to “What will be the output of the following C code if the input entered as first and second number is 5 and 6 respectively? #include<stdio.h> #include<stdlib.h> main() { int *p; p=(int*)calloc(3*sizeof(int)); printf("Enter first number\n"); scanf("%d",p); printf("Enter second number\n"); scanf("%d",p+2); printf("%d%d",*p,*(p+2)); free(p); }”. This question is standard in competitive examination syllabi for Memory Allocation.

welcome is the correct answer to “What will be the output of the following C code? #include<stdio.h> #include<stdlib.h> void main() { char *p = calloc(100, 1); p = "welcome"; printf("%s\n", p); }”. This question is standard in competitive examination syllabi for Memory Allocation.

Tree is the correct answer to “Which of the following is an example for non linear data type”. This question is standard in competitive examination syllabi for Memory Allocation.

Stack is the correct answer to “Local variables are stored in an area called . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.

NULL pointer is the correct answer to “If the space in memory allocated by malloc is not sufficient, then an allocation fails and returns . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.

Dangling pointer is the correct answer to “The following C code is an example of . . . . . . . . #include<stdio.h> #include<stdlib.h> #include<string.h> main() { char *p,*q; p=(char*)malloc(3*sizeof(char)); q=p; strcpy(p,"hello"); printf("p=%s",p); printf("q=%s",q); free(q); q=NULL; gets(p); gets(q); printf("%s",p); printf(“%s”,q); }”. This question is standard in competitive examination syllabi for Memory Allocation.

void* is the correct answer to “If malloc() and calloc() are not type casted, the default return type is . . . . . . . .”. This question is standard in competitive examination syllabi for Memory Allocation.