字符串 字符指针（1）

char *p1="abcd",*p2="abcd";//如果 *p2="abcdef"，则结果是：no equal
if(p1==p2) 
	cout<<"p1 p2 equal \n";
else  
    cout<<"p1 p2 no equal \n";

if("join"=="join")         //如果 "join"=="joinn"，则结果是：no equal
	cout<<"equal \n";
else   
      cout<<"no equal \n";
  
char a1[10]="12345",a2[10]="12345";  //"12345"是字符串，不是字符串常量
if(a1==a2)
     cout<<"a1[] a2[] equal \n";
else 
	cout<<"a1[] a2[] no equal \n";


char *p3="abcd",a[10]="7890";
cout<<*p3<<" "<<*(p3+2)<<" "<<p3<<endl;
cout<<*a<<" "<<*(a+2)<<" "<<a<<endl;
p3="1234";           // 可以
cout<<*p3<<" "<<*(p3+2)<<" "<<p3<<endl;
  //a="jkliu";         //error：不可以