Question

Is there anything wrong with the following program? Do I have to delete the pointers so I don’t have a memory leaks?

Please help.

#include<iostream>
using namespace std;
int main()
{
int x=2, y=3;
int *p,*q;
int **pp;

cout<<x<<","<<y<<endl;//x=2,y=3
p=&x;
q=&y;
cout<<*p<<","<<*q<<endl;//*p=2,*q=3
p=new int [5];
p[2]=9;
q=p+x;
p[0]=8;

cout<<*p<<","<<*q<<endl;//*p=8,*q=9

pp=&p;

cout<<pp[0][2]<<endl;//pp[0][2]=9

q=new int;
p=q;
*p=5;
*q=7;

cout<<*p<<","<<*q<<endl;//*p=7,*q=7
delete p;
p=NULL;
}

Answer 1

You are allocating memory for p and q:

p=new int [5];
/* ... */
q=new int;

But you are only freeing p using an invalid operator, since arrays should be deleted using delete[]. You should at some point free both p and q using:

delete[] p;
delete q;

Note that since you are making your pointers point to the other pointer’s allocated buffer, you might have to check which delete operator corresponds to which new operation.

You should use delete[] on the buffer allocated with new[] and delete with the buffer allocated with new.