std::vector size() method

od C++20

// prism-push-types:size_type
// Const version only
constexpr size_type size() const noexcept;

od C++11

// prism-push-types:size_type
// Const version only
size_type size() const noexcept;

do C++11

// prism-push-types:size_type
// Const version only
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.

Complexity

Constant - O(1).

Example

Main.cpp

#include <array>
#include <iostream>
 
int main()
{ 
    std::vector<int, 4> nums {1, 3, 5, 7};
 
    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output

nums contains 4 elements.