std::vector<T,Allocator>::size (3) - Linux Manuals

std::vector<T,Allocator>::size: std::vector<T,Allocator>::size

NAME

std::vector<T,Allocator>::size - std::vector<T,Allocator>::size

Synopsis


size_type size() const; (until C++11)
size_type size() const noexcept; (since C++11)


Returns the number of elements in the container, i.e. std::distance(begin(), end()).

Parameters


(none)

Return value


The number of elements in the container.

Complexity


Constant.

Example


The following code uses size to display the number of elements in a std::vector<int>:
// Run this code


  #include <vector>
  #include <iostream>


  int main()
  {
      std::vector<int> nums {1, 3, 5, 7};


      std::cout << "nums contains " << nums.size() << " elements.\n";
  }

Output:


  nums contains 4 elements.

See also


         returns the number of elements that can be held in currently allocated storage
capacity (public member function)
         checks whether the container is empty
empty (public member function)
         returns the maximum possible number of elements
max_size (public member function)
         changes the number of elements stored
resize (public member function)

Pages related to std::vector<T,Allocator>::size