public member function

vector::push_back

void push_back ( const T& x );
Add element at the end
Adds a new element at the end of the vector, after its current last element. The content of this new element is initialized to a copy of x.

This effectively increases the vector size by one, which causes a reallocation of the internal allocated storage if the vector size was equal to the vector capacity before the call. Reallocations invalidate all previously obtained iterators, references and pointers.

Parameters

x
Value to be copied to the new element.
T is the first template parameter (the type of the elements stored in the vector).

Return value

none

If a reallocation happens, it is performed using Allocator::allocate(), which may throw exceptions (for the default allocator, bad_alloc is thrown if the allocation request does not succeed).

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
 
// vector::push_back
#include <iostream>
#include <vector>
using namespace std;

int main ()
{
  vector<int> myvector;
  int myint;

  cout << "Please enter some integers (enter 0 to end):\n";

  do {
    cin >> myint;
    myvector.push_back (myint);
  } while (myint);

  cout << "myvector stores " << (int) myvector.size() << " numbers.\n";

  return 0;
}

The example uses push_back to add a new element to the vector each time a new integer is read.

Complexity

Constant (amortized time, reallocation may happen).

See also

vector::pop_back
Delete last element (public member function)
vector::insert
Insert elements (public member function)