Question on simple C++ program with pointers

[rjp1]

Question on the below c++ code, 3rd line from bottom of below code, the line :

cout << ps << " at " << (int *) ps << endl;

It prints out "fox at 0xb82b78"

when I change it to :
cout << ps << " at " << ps << endl;

It still prints out "fox at 0xb82b78"
expected behavior - print "fox at fox"

I thought if you want to see the Address of the string (ps) you have to type cast
the pointer to another pointer type, such as (int *) ?


// ------------------------------
// c++ program
#include <iostream>
#include <cstring>

using namespace std;

int main()
{
char animal[20] = "bear"; // animal holds bear
const char* bird = "wren"; // bird holds address of string
char* ps; // uninitialized

cout << animal << " and "; // display bear
cout << bird << "\n"; // display wren
//cout << ps << "\n"; // may display garbage, may cause crash

cout << "Enter a kind of animal: ";
cin >> animal; // ok if input is < 20 characters
//cin >> ps; // to horrible to try; ps doesn't point
// to allocated space

ps = animal; // set ps to point to string
cout << ps << "!\n"; // ok, same is using animal
cout << "Before using strcpy():\n";
cout << animal << " at " << (int *) animal << endl;
cout << ps << " at " << (int *) ps << endl;

ps = new char[strlen(animal) + 1]; // get new storage
strcpy(ps, animal); // copy string to new storage

cout << "After using strcpy():\n";
cout << animal << " at " << (int*) animal << endl;
cout << ps << " at " << (int *) ps << endl;
delete [] ps;

return 0;
}

[Paul McKenzie]

Question on the below c++ code, 3rd line from bottom of below code, the line :

cout << ps << " at " << (int *) ps << endl;

It prints out "fox at 0xb82b78"

when I change it to :
cout << ps << " at " << ps << endl;

It still prints out "fox at 0xb82b78"

What you mentioned is impossible, unless the compiler is horribly broken. Why would the first "ps" print out "fox", but the second "ps" in that line print out an address? Maybe you are confused as to what program you were running, or some other issue.

Also, why didn't you post the program you mentioned above? Instead you posted a different program (and without code tags -- please use code tags when posting code).

#include <iostream>
#include <cstring>

using namespace std;

int main()
{
    char animal[20] = "bear"; // animal holds bear
    const char* bird = "wren"; // bird holds address of string
    char* ps; // uninitialized

    cout << animal << " and "; // display bear
    cout << bird << "\n"; // display wren

    cout << "Enter a kind of animal: ";
    cin >> animal; // ok if input is < 20 characters

    ps = animal; // set ps to point to string
    cout << ps << "!\n"; // ok, same is using animal
    cout << "Before using strcpy():\n";
    cout << animal << " at " << (int *) animal << endl;
    cout << ps << " at " << (int *) ps << endl;

    ps = new char[strlen(animal) + 1]; // get new storage
    strcpy(ps, animal); // copy string to new storage

    cout << "After using strcpy():\n";
    cout << animal << " at " << (int*) animal << endl;
    cout << ps << " at " << (int *) ps << endl;
    delete [] ps;

    return 0;
}

So change that program above to one you say doesn't work as expected.

Regards,

Paul McKenzie