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std::set::size

From cppreference.com
< cpp‎ | container‎ | set
size_type size() const;

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

Contents

[edit] Parameters

(none)

[edit] Return value

The number of elements in the container.

[edit] Exceptions

(none) (until C++11)
noexcept specification:  
noexcept
  
(since C++11)

[edit] Complexity

Constant.

[edit] 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.

[edit] See also

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