Skip to content
Related Articles

Related Articles

Improve Article
Save Article
Like Article

set::swap() in C++ STL

  • Difficulty Level : Basic
  • Last Updated : 14 Jan, 2018

Sets are a type of associative containers in which each element has to be unique, because the value of the element identifies it. The value of the element cannot be modified once it is added to the set, though it is possible to remove and add the modified value of that element.

set::swap()
This function is used to exchange the contents of two sets but the sets must be of same type, although sizes may differ.

Want to learn from the best curated videos and practice problems, check out the C++ Foundation Course for Basic to Advanced C++ and C++ STL Course for foundation plus STL.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

Syntax:

set1.swap(set2)

Return value: None



Examples:

Input  : set1 = {1, 2, 3, 4}
         set2 = {5, 6, 7, 8}
         set1.swap(set2);
Output : set1 = {5, 6, 7, 8}
         set2 = {1, 2, 3, 4}

Input  : set1 = {'a', 'b', 'c', 'd'}
         set2 = {'w', 'x', 'y', 'z'}
         set1.swap(set2);
Output : set1 = {'w', 'x', 'y', 'z'}
         set2 = {'a', 'b', 'c', 'd'}




// CPP program to illustrate
// Implementation of swap() function
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    // Take any two sets
    set<int> set1{ 1, 2, 3, 4 };
    set<int> set2{ 5, 6, 7, 8 };
  
    // Swap elements of sets
    set1.swap(set2);
  
    // Print the first set
    cout << "set1 = ";
    for (auto it = set1.begin();
         it != set1.end(); ++it)
        cout << ' ' << *it;
  
    // Print the second set
    cout << endl
         << "set2 = ";
    for (auto it = set2.begin();
         it != set2.end(); ++it)
        cout << ' ' << *it;
  
    return 0;
}

Output:

set1 =  5 6 7 8
set2 =  1 2 3 4

Time complexity: Constant

My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!