实例 C++ 传递引用参数

#include <iostream>

using namespace std;

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void swapNums(int &x, int &y) {

  int z = x;

  x = y;

  y = z;

}

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int main() {

  int firstNum = 10;

  int secondNum = 20;

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  cout << "Before swap: " << "\n";

  cout << firstNum << secondNum << "\n";

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  swapNums(firstNum, secondNum);

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  cout << "After swap: " << "\n";

  cout << firstNum << secondNum << "\n";

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  return 0;

}

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