#include //所谓值传递,就是函数调用时实参将数值传递给形参 //值传递时,如果形参发生,并不会影响实参 //值传递 //定义函数,实现两个数字进行交换函数 //如果函数不需要返回值,声明的时候可以写 void #if(0) void swap(int num1, int num2) { std::cout << "交换前的数字是:" << std::endl; std::cout << "num1 = " << num1 << std::endl; std::cout << "num2 = " << num2 << std::endl; int temp = num1; num1 = num2; num2 = temp; std::cout << "交换后的数字是:" << std::endl; std::cout << "num1 = " << num1 << std::endl; std::cout << "num2 = " << num2 << std::endl; //return; 无返回值或不需要返回值的时候,可以不写return } int main3() { int a = 10; int b = 20; std::cout << "a = " << a << std::endl; std::cout << "b = " << b << std::endl; //当我们做值传递的时候,函数的形参发生变化,并不会影响实参 swap(a, b); std::cout << "a = " << a << std::endl; std::cout << "b = " << b << std::endl; system("pause"); return 0; } #endif