Kirolos Emad
35
Q:

vector iterator in c++

#include <iostream>
#include <vector>
using namespace std;

vector<int> myvector;

for (vector<int>::iterator it = myvector.begin();
     it != myvector.end();
     ++it)
   cout << ' ' << *it;
cout << '\n';
1
// EXAMPLE
vector<string> vData;
vData.push_back("zeroth");
vData.push_back("first");
vData.push_back("second");
vData.push_back("third");

std::vector<string>::iterator itData;

for (itData = vData.begin(); itData != vData.end() ; itData++)
{
  auto ElementIndex = itData-vData.begin();
  auto ElementValue = vData[ElementIndex]; // vData[ElementIndex] = *itData
  cout << "[ElementIndex:" << ElementIndex << "][ElementValue:" << ElementValue << "]\n";
}

/* HEADER(S)
#include <vector>
#include <iostream>
using namespace std;
*/
1
// C++ program to demonstrate iterators 
  
#include <iostream> 
#include <vector> 
using namespace std; 
int main() 
{ 
    // Declaring a vector 
    vector<int> v = { 1, 2, 3 }; 
  
    // Declaring an iterator 
    vector<int>::iterator i; 
  
    int j; 
  
    cout << "Without iterators = "; 
      
    // Accessing the elements without using iterators 
    for (j = 0; j < 3; ++j)  
    { 
        cout << v[j] << " "; 
    } 
  
    cout << "\nWith iterators = "; 
      
    // Accessing the elements using iterators 
    for (i = v.begin(); i != v.end(); ++i) 
    { 
        cout << *i << " "; 
    } 
  
    // Adding one more element to vector 
    v.push_back(4); 
  
    cout << "\nWithout iterators = "; 
      
    // Accessing the elements without using iterators 
    for (j = 0; j < 4; ++j)  
    { 
        cout << v[j] << " "; 
    } 
  
    cout << "\nWith iterators = "; 
      
    // Accessing the elements using iterators 
    for (i = v.begin(); i != v.end(); ++i)  
    { 
        cout << *i << " "; 
    } 
  
    return 0; 
} 
2
vector<int>::iterator ptr; 
1
// C++ code to demonstrate the working of 
// iterator, begin() and end() 
#include<iostream> 
#include<iterator> // for iterators 
#include<vector> // for vectors 
using namespace std; 
int main() 
{ 
    vector<int> ar = { 1, 2, 3, 4, 5 }; 
      
    // Declaring iterator to a vector 
    vector<int>::iterator ptr; 
      
    // Displaying vector elements using begin() and end() 
    cout << "The vector elements are : "; 
    for (ptr = ar.begin(); ptr < ar.end(); ptr++) 
        cout << *ptr << " "; 
      
    return 0;     
} 
0

New to Communities?

Join the community