C++ empty()

In C++, the empty() method for std::set determines whether the set contains no elements. It returns true if the container is empty and false otherwise.

Syntax

set_name.empty()

Parameters:

This method does not take any parameters.

Return Values:

Returns true if the container is empty and false otherwise.

Example: Using empty() with std::set

The code below demonstrates how to use the empty() method with std::set in C++, printing a message based on whether the set is empty or not:

#include <iostream>
#include <set>

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

  if (my_set.empty())
    std::cout << "Set is empty\n";
  else
    std::cout << "Set has elements\n";

  std::set<int> my_other_set{2, 4, 3};

  if (my_other_set.empty())
    std::cout << "Set is empty\n";
  else
    std::cout << "Set has elements\n";

  return 0;
}

Copy to clipboard
Copy to clipboard

The output of the above code is:

Set is empty
Set has elements

Copy to clipboard
Copy to clipboard

Codebyte Example: Using empty() to Calculate a Sum

In this example, the empty() method helps control a loop that sums and removes elements until the set becomes empty:

Visit us
Visit us
Hide code
Code
Output
Hide output
Loading...
Copy to your clipboard
Copy Codebyte
Run