how to iterate trough a vector in c++

for(auto const& value: a) {
     /* std::cout << value; ... */
}

vector<int> myVector;

myVector.push_back(1);
myVector.push_back(2);
myVector.push_back(3);
myVector.push_back(4);

for(auto x: myVector){
	cout<< x << " ";

}

vector<pair<int,int>> myVectorOfPairs;

myVectorOfPairs.push_back({1,2});
myVectorOfPairs.push_back({3,4});
myVectorOfPairs.push_back({5,6});
myVectorOfPairs.push_back({7,8});

for(auto x: myVectorOfPairs){
	cout<< x.first << " " << x.second << endl;

}

for (auto & element : vector) {
    element.doSomething ();
}

for(std::vector<T>::size_type i = 0; i != v.size(); i++) {
    v[i].doSomething();
}

vector<int> vi;
...
for(int i : vi) 
  cout << "i = " << i << endl;

for (vector<int Type>:: iter = myVector.begin(); iter != myVector.end(); iter++)
   (*iter)->display();