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public member function

<unordered_map>

std::unordered_map::size

size_type size() const noexcept;

Return container size

Returns the number of elements in the unordered_map container.

Parameters

none

Return Value

The number of elements in the container.

Member type

size_type is an unsigned integral type.

Example

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// unordered_map::size
#include <iostream>
#include <string>
#include <unordered_map>

int main ()
{
  std::unordered_map<std::string,double> mymap = {
       {"milk",2.30},
       {"potatoes",1.90},
       {"eggs",0.40}
  };

  std::cout << "mymap.size() is " << mymap.size() << std::endl;

  return 0;
}

Output:


Complexity

Constant.

Iterator validity

No changes.

See also

unordered_map::max_size
Return maximum size (public member function)
unordered_map::empty
Test whether container is empty (public member function)