C Quiz – 101 | Question 3

#include "stdlib.h"
int main()
{
 int *pInt;
 int **ppInt1;
 int **ppInt2;

 pInt = (int*)malloc(sizeof(int));
 ppInt1 = (int**)malloc(10*sizeof(int*));
 ppInt2 = (int**)malloc(10*sizeof(int*));

 free(pInt);
 free(ppInt1);
 free(*ppInt2);
 return 0;
}

Choose the correct statement w.r.t. above C program.
(A) malloc() for ppInt1 and ppInt2 isn’t correct. It’ll give compile time error.
(B) free(*ppInt2) is not correct. It’ll give compile time error.
(C) free(*ppInt2) is not correct. It’ll give run time error.
(D) No issue with any of the malloc() and free() i.e. no compile/run time error.

Answer: (D)
Explanation: ppInt2 is pointer to pointer to int. *ppInt2 is pointer to int. So long as the argument of free() is pointer, there’s no issue. That’s why B) and C) both are not correct. Allocation of both ppInt1 and ppInt2 is fine as per their data type. So A) is also not correct. The correct statement is D).
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