C++ Set Library - clear Function

Description

It removes all elements from the set container.

Declaration

Following are the ways in which std::set::clear works in various C++ versions.

C++98

void clear();

C++11

void clear() noexcept;

Return value

none

Exceptions

It never throws exceptions.

Time complexity

Time complexity is contstant.

Example

The following example shows the usage of std::set::clear.

#include <iostream>
#include <set>

int main () {
   std::set<int> myset;

   myset.insert (10);
   myset.insert (20);
   myset.insert (30);

   std::cout << "myset contains:";
   for (std::set<int>::iterator it = myset.begin(); it!=myset.end(); ++it)
      std::cout << ' ' << *it;
   std::cout << '\n';

   myset.clear();
   myset.insert (111);
   myset.insert (222);

   std::cout << "myset contains:";
   for (std::set<int>::iterator it = myset.begin(); it!=myset.end(); ++it)
      std::cout << ' ' << *it;
   std::cout << '\n';

   return 0;
}

The above program will compile and execute properly.

myset contains: 10 20 30
myset contains: 111 222