help with iterator & array

[jonathan710]

// Expect to print values of arr[0] to arr[4]
    #include <iostream>
    #include <vector>
    using namespace std;
    int main() {
        vector<int *> ptrList;
        int arr[] = { 0, 10, 20, 30, 40 };
        int * ptrArr = arr;
        for( int i=0; i< 5; i++ ) {
            ptrList.push_back( ptrArr+i );
        }
        vector<int *>::iterator itr = ptrList.begin();
        for( int i=1; i<= 5; i++ ) {
            cout << **itr-1 << endl;
            itr++;
        }
        return 0;
    }

somebody help me please...dunno where i went wrong :(

[nullptr]

At line 12 you've declared an iterator: vector<int *>::iterator itr = ptrList.begin();
So just use it to iterate through the vector.

 vector<int *>::iterator itr = ptrList.begin();
 for( itr; itr < ptrList.end(); ++itr ) {
     cout << **itr << endl;
 }

[DeanMSands3]

Beat me to it again!
I'll just add that itr isn't directly affected by i, so the first run through when itr is at the beginning, itr-1 is pointing at something that's not there.

[richieking]

Take of the code from line 12-16 and use this
dont forgrt to include the algorithm lib

for_each(ptrList.begin(),ptrList.end(),[](int *c){ cout << *c-1;});

[nullptr]

for_each(ptrList.begin(),ptrList.end(),[](int *c){ cout << *c-1;});

It should just be cout << *c, otherwise it's subtracting 1 from each value.
ie. -1, 9, 19 etc

for_each(ptrList.begin(), ptrList.end(), [](int *c){ 
    cout << *c << "\n";
});

[richieking]

Are you guessing?
Check the op's code before you comment. goto line 12-16. What do you see?...

Also you provided nothing new and no solution to the op. Check first. ))

[Tumlee]

Another way to print the values pointed to by the vector is to use C++11's new range-based for loops (if you have an up-to-date compiler). This way, you don't even have to declare your own iterator.

for(auto ptr : ptrList)
    cout << *ptr << endl;

[nullptr]

Are you guessing?
Check the op's code before you comment. goto line 12-16. What do you see?...

Also you provided nothing new and no solution to the op. Check first. ))

I assume you're addressing me?
1. No, I'm not guessing.
2. line 1: Expect to print values of arr[0] to arr[4]. So at lines 12 to 16 I see an obvious mistake.
3. I always check. I have no interest in posting for the sake of increasing my post count.