c++将引用作为函数的参数---6

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引用经常被用作函数参数，使得函数中的变量名成为调用程序中的变量别名。这种传递参数 的方法称为按引用传递。按引用传递允许被调用的函数能够访问调用函数中的变量。C++新增这项特性是对C语言的超越，C语言只能按值传递。按值传递导致被 调用函数使用调用程序的值得拷贝。当然，C语言也允许避开按值传递的限制，采用按指针传递的方式。

代码：

        #include <stdio.h>    
        #include <iostream>  
          
        using namespace std;  
          
        void TestAddress1(int p, int& a, int b)  
        {  
            cout << "TestAddress1" << endl;  
            cout << "p address:" << &p << "; p value:" << p << endl;  
            cout << "a address:" << &a << "; a value:" << a << endl;  
            cout << "b address:" << &b << "; b value:" << b << endl;  
          
            int* c = &b;  
            c -= 2;  
            cout << "c address:" << c << "; c value:" << *c << endl;  
        }  
          
        void TestAddress2(int* a, int b)  
        {  
            cout << "TestAddress2" << endl;  
            cout << "a address:" << &a << "; a value:" << *a << endl;  
            cout << "b address:" << &b << "; b value:" << b << endl;  
        }  
          
        int main()  
        {  
            int* a = new int[5];  
            memset(a, 0, sizeof(int)* 5);  
            a[0] = 123;  
            int b = 2;  
            int c = 3;  
          
            cout << "out a address:" << &a << endl;  
            cout << "out b address:" << &b << endl;  
            cout << "out c address:" << &c << endl;  
          
            cout << "-----------------" << endl;  
          
            TestAddress1(b, b, c);  
          
            cout << "-----------------" << endl;  
          
            TestAddress2(a, b);  
        }