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pointers to vectors

rofhiwangae (34)
hey guys am trying out something new but i need some srs help i have two code below the first compiles and run bt de second also runs bt crashes...so my question is y is different when i put my vector as an argument as shown in first code and when i just declare it within my function in second code; thanx in advance 

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 #include <iostream>
#include <vector>

using namespace std;

void  cube(vector<string> *numbers)
{


    numbers->push_back("5");
    numbers->push_back("4");
    numbers->push_back("hsbfjbfsjbfjbjwbdfwjhdfw");
    numbers->push_back("2");
    numbers->push_back("1");

    cout<<numbers->at(2);
}
int main()
{
    
    vector<string>num;
    cube(&num);

    return 0;
} 


second code 


#include <iostream>
#include <vector>

using namespace std;

void  cube()
{
vector<string> *numbers;

    numbers->push_back("5");
    numbers->push_back("4");
    numbers->push_back("hsbfjbfsjbfjbjwbdfwjhdfw");
    numbers->push_back("2");
    numbers->push_back("1");

    cout<<numbers->at(2);
}
int main()
{

   // vector<string>num;
    cube();

    return 0;
}
mutexe (2372)
you have a "real" vector instantiated in the first example (line) 21 and you pass a reference to this into your function.
In second example you don't. You just have a pointer to a vector. You'd have to new one up.
Last edited on
rofhiwangae (34)
thanx for de reply but hw would i initiate dat in my second code...i have seen "new" bt dont knw how to use it
mutexe (2372)
take a look here:
http://stackoverflow.com/questions/6946217/pointer-to-a-vector

at the answer that's had 27 up-votes. The important thing to realise is that this:
vector<string> *numbers;
is not really creating a vector.
Last edited on
rofhiwangae (34)
thanx i got it
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