Reference
C Library
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STL Containers
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vector::vector
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member functions:
vector::assign
vector::at
vector::back
vector::begin
vector::capacity
vector::clear
vector::empty
vector::end
vector::erase
vector::front
vector::get_allocator
vector::insert
vector::max_size
vector::operator=
vector::operator[]
vector::pop_back
vector::push_back
vector::rbegin
vector::rend
vector::reserve
vector::resize
vector::size
vector::swap


vector::size

public member function
size_type size() const;

Return size

Returns the number of elements in the vector container.

This is the number of actual objects held in the vector, which is not necessarily equal to its storage capacity. Vectors automatically reallocate their storage space when needed or when requested with member resize. To retrieve the current storage capacity of a vector you can call to its member capacity.

Parameters

none

Return Value

The number of elements that conform the vector's content.

Member type size_type is an unsigned integral type.

Example

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// vector::size
#include <iostream>
#include <vector>
using namespace std;
int main ()
{
  vector<int> myints;
  cout << "0. size: " << (int) myints.size() << endl;
  for (int i=0; i<10; i++) myints.push_back(i);
  cout << "1. size: " << (int) myints.size() << endl;
  myints.insert (myints.end(),10,100);
  cout << "2. size: " << (int) myints.size() << endl;
  myints.pop_back();
  cout << "3. size: " << (int) myints.size() << endl;
  return 0;
}


Output:
0. size: 0
1. size: 10
2. size: 20
3. size: 19

Complexity

Constant.

See also

vector::capacity Return size of allocated storage capacity (public member function)
vector::resize Change size (public member function)
vector::max_size Return maximum size (public member function)