exchange() Function in C++ 14
The exchange() function is a built-in function in C++ 14 defined in the <utility> header. The exchange() function copies new value to old value and it will return the old value.
Syntax:
exchange(old, new)
Parameters: The function needs two parameters.
- The parameter needs to be set.
- The parameter with which we wanted to set our parameter 1
Return Value: It returns the old value which means the parameter that needs to be set
Example 1:
C++14
// C++ Program to demonstrate // exchange() #include <iostream> #include <utility> using namespace std; int main() { int x = 10; int y = 20; // Setting value of y to x exchange(x, y); cout << "Value of x:" << x << '\n' << "Value of y:" << y << endl; int a = 40; int b = 30; // Setting value of b to a and copying a to b b = exchange(a, b); cout << "Value of a:" << a << '\n' << "Value of b:" << b << endl; return 0; } |
Output
Value of x:20 Value of y:20 Value of a:30 Value of b:40
Example 2:
C++14
// C++ Program to demonstrate // exchange() #include <iostream> #include <utility> #include <vector> using namespace std; int main() { // We can also set one vector // values to another vector vector< int > v1 = { 2, 4, 6, 8 }; vector< int > v2 = { 1, 3, 5, 7 }; v2 = exchange(v1, v2); cout << "Values of v1 after exchange:" << endl; for ( auto ele : v1) { cout << ele << " " ; } cout << endl; cout << "Values of v2 after exchange:" << endl; for ( auto ele : v2) { cout << ele << " " ; } return 0; } |
Output
Values of v1 after exchange: 1 3 5 7 Values of v2 after exchange: 2 4 6 8