指针 * &

 1 int main()
 2 {
 3 int updates=6;   //定义int变量updates
 4 int * p_updates; //定义指针p_updates
 5 p_updates=&updates;//将updates的地址赋给指针p_upfates
 6 
 7 cout<<"value:update="<<updates<<endl;  //updates=6
 8 cout<<"*p_updates="<<*p_updates<<endl; //*p_updates为地址中存储的值 即6
 9 
10 cout<<"address:&updates="<<&updates<<endl; //&update 取地址
11 cout<<"p_updates="<<p_updates<<endl;  //p_updates 地址值
12 
13 *p_updates=*p_updates+1; //地址中存储的值加1 即6+1=7
14 cout<<"now updates="<<updates<<endl; //update=7
15 system("pause");
16 return 0;
17 }

 1 int main()
 2 {
 3 int higgens=5;
 4 int *pt=&higgens;
 5 
 6 cout<<"value of higgens="<<higgens<<endl;  //5
 7 cout<<"address of higgens="<<&higgens<<endl;  //地址 
 8 cout<<"value of *pt="<<*pt<<endl; //5
 9 cout<<"value of pt="<<pt<<endl;  //地址
10 system("pause");
11 }

 1 int main()
 2 {
 3     double * p3=new double [3];//定义一个double类型的指针
 4     p3[0]=0.2;
 5     p3[1]=0.5;
 6     p3[2]=0.8;
 7     cout<<"p3[1] is"<<p3[1]<<endl;  //p3当做数组名使用，p3[1]为第二个元素
 8     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
 9     cout<<"now p3[0] is"<<p3[0]<<endl;
10     cout<<"p3[1] is"<<p3[1]<<endl;
11     p3=p3-1; //为delete []提供正确的地址
12     delete [] p3;
13 
14     system("pause");
15     return 0;
16 }

 1 int main()
 2 {
 3     double wages[3]={10000.0,20000.0,30000.0};
 4     short stacks[3]={3,2,1};
 5     double *pw=wages;
 6     short *ps=&stacks[0];
 7 
 8     cout<<"pw="<<pw<<",*pw="<<*pw<<endl;
 9     pw=pw+1;
10     cout<<"pw="<<pw<<",*pw="<<*pw<<endl;
11     cout<<"ps="<<ps<<",*ps="<<*ps<<endl;
12     ps=ps+1;
13     cout<<"ps="<<ps<<",*ps="<<*ps<<endl;
14     cout<<"stacks[0]="<<stacks[0]<<",stacks[1]="<<stacks[1]<<endl;
15     cout<<"*stacks="<<*stacks<<",*(stacks+1)="<<*(stacks+1)<<endl;
16 
17     cout<<sizeof(wages)<<"=size of wages array"<<endl;//数组长度 3*8=24
18     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
19     system("pause");
20     return 0;
21 }