std::set::size

 

C++

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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

noexcept specification:  

noexcept

  (since C++11)

Complexity

Constant

Example

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

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

Output:

nums contains 4 elements.

See also

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