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

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

# Declarations

size_type size() const;

(noexcept since C++11)(constexpr since C++20)

# Return value

The number of elements in the container.

# Example

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

# See also