std::list::size

From cppreference.com
< cpp‎ | container‎ | list
size_type size() const;

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.

Exceptions

(none) (until C++11)
noexcept specification:  
noexcept
  
(since C++11)

Complexity

Constant or linear. (until C++11)
Constant. (since C++11)

Example

The following code uses size to display the number of elements in a std::list:

#include <list>
#include <iostream>
 
int main()
{ 
    std::list<int> nums {1, 3, 5, 7};
 
    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output:

nums contains 4 elements.

See also

checks whether the container is empty
(public member function)
returns the maximum possible number of elements
(public member function)
changes the number of elements stored
(public member function)