C++ set cend()

C++ set cend() function is used to return a constant iterator which is next to the last entry in the set.

Note:- This is a placeholder. No element exists in this location and attempting to access is undefined behavior.

Syntax

A const_iterator is an iterator that points to constant content.

Parameter

None

Return value

It returns a constant iterator which is pointing next to the last element of the set.

Complexity

Constant.

Iterator validity

No changes.

Data Races

The container is accessed.

Concurrently accessing the elements of a set is safe.

Exception Safety

This member function never throws exceptions.

Example 1

Let's see the simple example for cend() function:

#include <iostream>
#include <set>

int main ()
{
  std::set<int> myset = {60,20,40,50,10,30};

  std::cout << "myset contains:";
  for (auto it=myset.cbegin(); it != myset.cend(); ++it)
    std::cout << ' ' << *it;

  std::cout << '\n';

  return 0;
}

Output:

myset contains: 10 20 30 40 50 60

In the above example, cend() function is used to return an iterator pointing next to the last element in the myset set.

Example 2

Let's see a simple example to find the element in the set:

#include <iostream>
#include <string>
#include <set>

using namespace std;

int main ()
{
    int val;
    set<int> c = {10,20,30,40,50};
 
    cout<<"Enter value to find: ";
    cin>>val;

    auto result = c.find(val);  
    
    //find until end of the set elements
    if (result != c.cend()) {  
        cout << "Element found: "<< *result; 
        cout << endl;  
    } else {  
        cout << "Element not found." << endl;  
    }  
    
  return 0;
}

Output:

Enter value to find: 10
Element found: 10

Example 3

Let's see a simple example to iterate over the set using while loop:

#include <iostream>
#include <set>
#include <string>
int main()
{
    using namespace std;
 
    set<string> myset = {"Orange", "Banana", "Apple"};

    set<string>::const_iterator it; // declare an iterator
    
    it = myset.cbegin(); // assign it to the start of the set
    
    while (it != myset.cend()) // while it hasn't reach the end
    {
        cout << *it <<endl; 
        // print the value of the element it points to
        ++it; // and iterate to the next element
    }
    cout << endl;
}

Output:

Apple
Banana
Orange

In the above example, cend() function is used to return an iterator pointing next to the last element in the myset set.

Example 4

Let's see a simple example:

#include <iostream>
#include <set>
#include <algorithm>

using namespace std;

int main()
{
  set<int> c = {3, 1, 2};

  for_each(c.cbegin(), c.cend(), [](const int& x) {
    cout << x << endl;
  });
  
  return 0;
}

Output: