std::vector<T,Allocator>::size - cppreference.com (original) (raw)

| size_type size() const; | | (noexcept since C++11) (constexpr since C++20) | | ------------------------ | | ---------------------------------------------- |

Returns the number of elements in the container.

[edit] Return value

std::distance(begin(), end())

[edit] Complexity

Constant.

[edit] Example

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

#include #include   int main() { std::vector nums; assert(nums.size() == 0); nums = {1, 2, 3, 4}; assert(nums.size() == 4); }

[edit] See also

| | returns the number of elements that can be held in currently allocated storage (public member function) [edit] | | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | checks whether the container is empty (public member function) [edit] | | | returns the maximum possible number of elements (public member function) [edit] | | | changes the number of elements stored (public member function) [edit] | | | returns the size of a container or array (function template) [edit] |