Explaination for pointer mcq

#1

sir is there any explanation mcq of pointers

Question in mcq pointers
#2

which question Explanation you want
we will explain you.

#3

4 What is the problem with the following code #include<stdio.h>
int main()
{
int *ptr = (int *)malloc(sizeof(int));
ptr = NULL;
free(ptr);
}
A) Dangling Pointer
B) Memory leak
C) The program may crash as free() is called for NULL pointer.
D) Compiler Error

Q­6 What will be the output of the following program? #include
using namespace std;
int main() {
int arr[]={0,1,2,3,4};
int i, ptr;
for(ptr= arr, i=0; ptr+i <= arr+4; ptr++, i++) cout<<(ptr+i);
return 0;
}
A) 01234
B) 024
C) 234
D) 12340

Q­7 In the piece of code, arr[ ][ ] is a 2­D array and assume that the
contents of the 2­D array are already filled up. What is stored in the
variable sum at the end of the code segment?
int arr[3][3];
int i, sum=0; i = 0; while(i<3) {
sum += * ( * (arr+i)+(i++)); }
printf(“sum:%d”, sum);
A) Sum of all elements in the matrix
B) Sum of alternate elements in the matrix
C) Sum of the elements along the principal diagonal
D) None
Q­8 Would the following program compile?
#include
using namespace std;
int main() {
int a=10, *j; void *k; j=k=&a; j++;
k++; cout<<j<<k; return 0;
}

Detailed solutions to the questions in the MCQ sheet and not just the answers
#4

in question
ptr=arr means it holds the address of array’s first element
and i=0;
ptr+0<=arr+4 /// here we are comparing the addreses condition true
so output is 0
now ptr and i both inc so ptr+i reach at 2
so output is 2
simillarly for others.

in 8th ans is no because you can’t do j=k as both have different data types