Agfdhyk

I was practicing with array of pointers.
i wrote a simple code.

#include<iostream>

using namespace std;



int main(){



    int a[3]={1,2,3};

    int *b[3];



    for(int i=0; i<3; i++){

        b[i] = &a[i];

    }



    cout<<b; //This gives a confusing output

    cout<<endl;



    for(int i=0; i<3; i++){

        cout<<b[i];

        cout<<endl;

    }

}

and Output is

0x6ffe10

0x6ffe30

0x6ffe34

0x6ffe38

Now I don't understand where the b pointing.
I know this sounds weird but i wanna know.
where the b pointer pointing.
The b[0], b[1], b[2] gives expected result.

b is an array of pointers to int. It's address is the address of the first pointer.

• The first pointer b[0] is assigned the address of element a[0] (so b[0] points to 1).


• 
  b[1] is assigned the address of a[1] (so b[1] points to 2)


• 
  b[2] is assigned the address of a[2] (so b[2] points to 3)

In each case the pointer in the b array holds the address of the corresponding element within a. So if there are any changes made to the elements of a after your loop assigning the address in a to b, the value held in the memory location pointed to by the element of b will change, but the address for that value held by b will remain unchanged.

When b is passed to cout's << operator, it decays into a pointer; hence as far as the printing function is concerned, printing out b is the same as printing out &b[0].

Therefore, cout << b; prints out the address of the first pointer in the b[3] array. (Note that the address of the pointer is not the same thing as the address the pointer is pointing to! That can be a source of confusion -- just keep in mind that a pointer-variable is a variable as well, and like any other variable, it has its own unique location in memory, which is distinct from the location it is pointing at)

b is an array of pointers to int which is a local variable on the stack.

Its address does not depend on what individual elements of its array are assigned to.

If you print its value before the for loop (where you assign values to its members), you will see that it is the same as the value printed after the for loop.

See live demo here.

Pictorially:

b Memory adress of the whole array.