005_linuxC++之_指针的引入

（一）直接看代码

#include <iostream>
using namespace std;
int add(int a){
    a = a + 1;
    return a;
}
int add(int *a){
    *a = *a + 1;
    return *a;
}
int add_ref(int &b){
    b = b + 1;
    return b;
}
int main(int arg,char ** argv){
    int a = 99;
    int &c = a;                /*使用符号&来进行引用，引用之后c++就相当于a地址中的数进行a++*/
    cout<<add(a)<<endl;        /*传入的是参数*/  /*a = 100*/
    cout<<"a = "<<a<<endl;                      /*a = 99*/
    
    cout<<add(&a)<<endl;    /*传入的地址*/    /*a = 100*/
    cout<<"a = "<<a<<endl;                      /*a = 100*/

    cout<<add_ref(a)<<endl;    /*引用*/          /*a = 101*/
    cout<<"a = "<<a<<endl;                      /*a = 101*/
    
    c++;                                      /*a = 102*/
    cout<<"a = "<<a<<endl;                      /*a = 102*/
    cout<<"c = "<<c<<endl;                      /*a = 102*/
    return 0;
}

运行结果