std::vector<T,Allocator>::size
size_type size() const; | (noexcept since C++11) (constexpr since C++20) |
Returns the number of elements in the container, i.e., std::distance(begin(), end()).
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>:
#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
| returns the number of elements that can be held in currently allocated storage (public member function) |
|
| 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) |
|
|
(C++17)(C++20) | returns the size of a container or array (function template) |
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