Explore topic-wise MCQs in C Interview.

This section includes 22 Mcqs, each offering curated multiple-choice questions to sharpen your C Interview knowledge and support exam preparation. Choose a topic below to get started.

1.

The following C code is an example of __________

A. Memory leak
B. Dangling pointer
C. Static memory allocation
D. Linked listView Answer
Answer» C. Static memory allocation
Discussion
2.

The free() function frees the memory state pointed to by a pointer and returns ___________

A. the same pointer
B. the memory address
C. no value
D. an integer value
Answer» D. an integer value
Discussion
3.

In the function realloc(), if the new size of the memory block is larger than the old size, then the added memory ___________

A. is initialized to junk values
B. is initialized to zero
C. results in an error
D. is not initialized
Answer» E.
Discussion
4.

What will happens if the statement free(a) is removed in the following C code?

A. is removed in the following C code? a) Error
B. Memory leak
C. Dangling pointer arises
D. 200 is printed as outputView Answer
Answer» C. Dangling pointer arises
Discussion
5.

In the function malloc(), each byte of allocated space is initialized to zero.

A. True
B. False
Answer» C.
Discussion
6.

What will be the output of the following C code if the input entered as first and second number is 5 and 6 respectively?

A. 56
B. Address of the locations where the two numbers are stored
C. 57
D. ErrorView Answer
Answer» E.
Discussion
7.

If the space in memory allocated by malloc is not sufficient, then an allocation fails and returns ___________

A. NULL pointer
B. Zero
C. Garbage value
D. The number of bytes available
Answer» B. Zero
Discussion
8.

Garbage collector frees the programmer from worrying about ___________

A. Dangling pointers
B. Creating new objects
C. Memory leak
D. Segmentation errors
Answer» D. Segmentation errors
Discussion
9.

When the pointer is NULL, then the function realloc is equivalent to the function ___________

A. malloc
B. calloc
C. free
D. alloc
Answer» B. calloc
Discussion
10.

What will be the error (if any) in the following C code?

A. No error
B. Error in the statement: strcpy(p,”HELLO”);
C. Error in the statement: *p=(char)calloc(10);
D. Error in the statement: free(p);View Answer
Answer» D. Error in the statement: free(p);View Answer
Discussion
11.

Suppose we have a one dimensional array, named ‘x’, which contains 10 integers. Which of the following is the correct way to allocate memory dynamically to the array ‘x’ using malloc()?

A. x=(int*)malloc(10);
B. x=(int*)malloc(10,sizeof(int));
C. x=malloc(int 10,sizeof(int));
D. x=(int*)malloc(10*sizeof(int));
Answer» E.
Discussion
12.

What will be the output of the following C code if it is executed on a 32 bit processor?

A. 2
B. 4
C. 8
D. Junk valueView Answer
Answer» C. 8
Discussion
13.

The incorrect statement with respect to dangling pointers is ___________

A. Pointer pointing to non-existent memory location is called dangling pointer
B. When a dynamically allocated pointer references the original memory after it has been freed, a dangling pointer arises
C. If memory leak occurs, it is mandatory that a dangling pointer arises
D. Dangling pointer may result in segmentation faults and potential security risks
Answer» E.
Discussion
14.

Pick out the correct statement with respect to the heap.

A. Local variables are stored on the heap
B. Static variables are stored on the heap
C. Heap is the data structure which is used to implement recursive function calls
D. Everything on the heap is anonymous
Answer» B. Static variables are stored on the heap
Discussion
15.

is removed, what happens?

A. Error
B. Memory leak
C. Dangling pointer arises
D. 200 is printed as output
Answer» C. Dangling pointer arises
Discussion
16.

If malloc() and calloc() are not type casted, the default return type is ___________

A. void*
B. void**
C. int*
D. char*
Answer» D. char*
Discussion
17.

A condition where in memory is reserved dynamically but not accessible to any of the programs is called _____________

A. Memory leak
B. Dangling pointer
C. Frozen memory
D. Pointer leak
Answer» C. Frozen memory
Discussion
18.

Which of the following functions allocates multiple blocks of memory, each block of the same size?

A. malloc()
B. realloc()
C. calloc()
D. free()
Answer» B. realloc()
Discussion
19.

Suppose we have a one dimensional array, named ‘x’, which contains 10 integers. Which of the following is the correct way to allocate memory dynamically to the array ‘x’ using malloc()?$

A. x=(int*)malloc(10);
B. x=(int*)malloc(10,sizeof(int));
C. x=malloc(int 10,sizeof(int));
D. x=(int*)malloc(10*sizeof(int));
Answer» D. x=(int*)malloc(10*sizeof(int));
Discussion
20.

The number of arguments taken as input which allocating memory dynamically using malloc() is ___________

A. 0
B. 1
C. 2
D. 3
Answer» E.
Discussion
21.

56

A. Address of the locations where the two numbers are stored
B. 57
C. Error
Answer» C. Error
Discussion
22.

2

A. 4
B. 8
C. Junk value
Answer» C. Junk value
Discussion