指针 * &

int main()
{
int updates=6;   //定义int变量updates
int * p_updates; //定义指针p_updates
p_updates=&updates;//将updates的地址赋给指针p_upfates

cout<<"value:update="<<updates<<endl;  //updates=6
cout<<"*p_updates="<<*p_updates<<endl; //*p_updates为地址中存储的值 即6

cout<<"address:&updates="<<&updates<<endl; //&update 取地址
cout<<"p_updates="<<p_updates<<endl;  //p_updates 地址值

*p_updates=*p_updates+1; //地址中存储的值加1 即6+1=7
cout<<"now updates="<<updates<<endl; //update=7
system("pause");
return 0;
}

 

int main()
{
int higgens=5;
int *pt=&higgens;

cout<<"value of higgens="<<higgens<<endl;  //5
cout<<"address of higgens="<<&higgens<<endl;  //地址 
cout<<"value of *pt="<<*pt<<endl; //5
cout<<"value of pt="<<pt<<endl;  //地址
system("pause");
}

int main()
{
    double * p3=new double [3];//定义一个double类型的指针
    p3[0]=0.2;
    p3[1]=0.5;
    p3[2]=0.8;
    cout<<"p3[1] is"<<p3[1]<<endl;  //p3当做数组名使用，p3[1]为第二个元素
    p3=p3+1;//修改指针的值，+1之后p3[0]指向的是之前的第二个值
    cout<<"now p3[0] is"<<p3[0]<<endl;
    cout<<"p3[1] is"<<p3[1]<<endl;
    p3=p3-1; //为delete []提供正确的地址
    delete [] p3;

    system("pause");
    return 0;
}

int main()
{
    double wages[3]={10000.0,20000.0,30000.0};
    short stacks[3]={3,2,1};
    double *pw=wages;
    short *ps=&stacks[0];

    cout<<"pw="<<pw<<",*pw="<<*pw<<endl;
    pw=pw+1;
    cout<<"pw="<<pw<<",*pw="<<*pw<<endl;
    cout<<"ps="<<ps<<",*ps="<<*ps<<endl;
    ps=ps+1;
    cout<<"ps="<<ps<<",*ps="<<*ps<<endl;
    cout<<"stacks[0]="<<stacks[0]<<",stacks[1]="<<stacks[1]<<endl;
    cout<<"*stacks="<<*stacks<<",*(stacks+1)="<<*(stacks+1)<<endl;

    cout<<sizeof(wages)<<"=size of wages array"<<endl;//数组长度 3*8=24
    cout<<sizeof(pw)<<"=size of pw pointer"<<endl; //指针长度 4  在32位机上，所有指针类型变量占用内存字节数都为4 ，64位机指针占用的内存大小为8个字节
    system("pause");
    return 0;
}