The swap function in C++ algorithms exchanges or switches the values of two referenced containers.
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 simply exchanges the values between two containers without returning any output.
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 exhibits a complexity of N due to the need to swap each element individually. Conversely, for non-array data structures, the function maintains a constant complexity.
Data races
Both the containers are undergo modification
Exceptions
The function will raise an exception if any of the container elements also raises an exception.
