C++/Vector/vector at

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Use vector.at to change element in the vector

<source lang="cpp">

  1. include <iostream>

using std::cout; using std::endl;

  1. include <vector> // vector class-template definition
  2. include <algorithm> // copy algorithm
  3. include <iterator> // ostream_iterator iterator
  4. include <stdexcept> // out_of_range exception

int main() {

  int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
  std::vector< int > integers( array, array + 6 );
  std::ostream_iterator< int > output( cout, " " );
  integers.push_back( 2 );
  integers.push_back( 3 );
  integers.push_back( 4 );
  cout << "Vector integers contains: ";
  std::copy( integers.begin(), integers.end(), output );
  integers.at( 2 ) = 10; // set element at position 2 to 10
  cout << "\n\nVector integers contains: ";
  std::copy( integers.begin(), integers.end(), output );
  return 0;

} /* Vector integers contains: 1 2 3 4 5 6 2 3 4 Vector integers contains: 1 2 10 4 5 6 2 3 4

*/        
 </source>