C++ Algorithm swap function swaps or say interchanges the values of two containers under reference.
Syntax
Example
template<class T> void swap(T& a, T& b);
Parameter
a : It is the first container with some value.
b : It is another container with some value.
Return value
The function only swaps the values of two containers and does not return something.
Example 1
Example
#include <iostream>
#include <algorithm>
#include <vector>
int main ()
{
int a=14, b=9;
std::swap(a,b);
std::vector<int> sg (4,a), ss (6,b);
std::swap(sg,ss);
std::cout << "sg contains:";
for (std::vector<int>::iterator ti=sg.begin(); ti!=sg.end(); ti++)
std::cout << ' ' << *ti;
std::cout << '\n';
return 0;
}
Output:
Output
sg contains: 14 14 14 14 14 14
Example 2
Example
#include <bits/stdc++.h>
using namespace std;
int main()
{
int ss = 9;
int sg = 14;
cout << "Value of ss before swapping: " << ss << endl;
cout << "Value of sg before swapping: " << sg << endl;
swap(ss, sg);
cout << "Value of ss after swapping: " << ss << endl;
cout << "Value of sg after swapping: " << sg << endl;
return 0;
}
Output:
Output
Value of ss before swapping: 9
Value of sg before swapping: 14
Value of ss after swapping: 14
Value of sg after swapping: 9
Complexity
For arrays the function has N complexity as the operation of swapping is individually performed on each element. For non array the function has constant complexity.
Data races
Both the containers are undergo modification
Exceptions
The function throws an exception if any of the container elements throws one.