Understanding the vectors

[rajhansk]

// constructing vectors
#include <iostream>
#include <vector>

int main ()
{
// constructors used in the same order as described above:
std::vector<int> first; // empty vector of ints
std::vector<int> second (4,100); // four ints with value 100
std::vector<int> third (second.begin(),second.end()); // iterating through second
std::vector<int> fourth (third); // a copy of third

// the iterator constructor can also be used to construct from arrays:
int myints[] = {16,2,77,29};
std::vector<int> fifth (myints, myints + sizeof(myints) / sizeof(int) );

std::cout << "The contents of fifth are:";
for (std::vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)
std::cout << ' ' << *it;
std::cout << '\n';

return 0;
}



what is *it, in the above program, it has not even declared...

[TheIdeasMan]

what is *it, in the above program, it has not even declared...

Yeah it has, here:

for (std::vector<int>::iterator it = fifth.begin(); it != fifth.end(); ++it)

Iterators are like pointers, the * dereferences the iterator, giving the actual element.

Please always use code tags:
http://www.cplusplus.com/articles/z13hAqkS/