派生类成员函数在C ++中失败

Question

To make long story short:

class A {
        public:
              A();
              ~A();
              void SetID(char* ID);
              char* GetID();
        protected:
              char ID[10];
};

class B: public A {
        public:
              B();
              ~B();
        protected:
              ...
        private:
              ...
};

Then in main:

 ...
 B *temp = new B;
 temp->SetID("0x12345678");
 ...

Then the compiler said "Expected constructor,destructor or type conversion before -> token" where "temp->SetID("0x12345678")" lies

Anyone gimme some hints??

Whole Program as Loki suggested:

  #include <iostream>

  using namespace std;

  class A {
      public:
         A();
         ~A();
         void SetID(char* id);
         char* GetID();
       protected:
            char ID[10];
   };

   void A::SetID(char* id){
         strcpy(ID,id);          
    }
    char* A::GetID(){
         return ID;
    }
    class B: public A {
             public:
                 B();
                ~B();
             protected:
                int num;
     };


    int main(){
    B *temp = new B;
    B->SetID("0x12345678");
    cout<<B->GetID()<<endl;

    return 0;
    }

Answer 1

You are using B , which is a type, where you probably meant to use temp which is the name of the variable.

Instead of:

int main(){
B *temp = new B;
B->SetID("0x12345678");
cout<<B->GetID()<<endl;

return 0;
}

You probably meant:

int main(){
B *temp = new B;
temp->SetID("0x12345678");
cout<<temp->GetID()<<endl;

return 0;
}

which is more like the "excerpt" that you posted.

Answer 2

Let me guess.

You have closed main by an unpaired curly brace before you got to this code that you believe is in main . So it is outside of any function, and that is no place for expressions other than initializers.