C++ Set Library - begin Function

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Description

It returns an iterator referring to the first element in the set container.

Declaration

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

C++98

iterator begin();
const_iterator begin() const;

C++11

 iterator begin() noexcept;
const_iterator begin() const noexcept;

Return value

It returns an iterator referring to the first element in the set container.

Exceptions

It never throws exceptions.

Time complexity

Time complexity is contstant.

Example

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

#include <iostream>
#include <set>

int main () {
   int myints[] = {50,40,30,20,10};
   std::set<int> myset (myints,myints+10);

   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: 0 1 10 20 30 40 50 26390 2065620553