vector

[rookie123]

can anyone help me to write a swap function to swap 2 elements in the vector?
thanks

[Catfish666]

C++ already provides a "universal" swap function.
So by writing a swap() function yourself, you are reinventing the wheel.

http://www.cplusplus.com/reference/utility/swap/

[rookie123]

sorry, I don't mean to swap 2 vectors and I already tried the swap function in algorithm library and that didn't work either
this is what I been working on
I have a class that using the vector under the hood so I have a whole bunch of data in the vector. I am trying to swap 2 elements in the array it doesn't work and I am running out of time. thanks

[Catfish666]

The std::swap() function can be used to swap two elements.

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#include <iostream> #include <utility> #include <vector> int main() { std::vector<int> v1 {1, 1, 1, 1}; std::vector<int> v2 {2, 2, 2, 2}; std::swap(v1[1], v2[1]); std::swap(v1[3], v2[3]); std::cout << "v1 contents: "; for (int i: v1) std::cout << i << ' '; std::cout << "\nv2 contents: "; for (int i: v2) std::cout << i << ' '; std::cout << std::endl; }

v1 contents: 1 2 1 2 v2 contents: 2 1 2 1