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Lesson 5 External member functions
Objective Rewrite Person class using external member function

External Member Functions in C++

Use an external member function to print out the member data of the Person class.
To define a member function outside the class, the scope resolution operator is used. To illustrate this, let us revisit the ch_stack class from the previous module. We can change the declaration of push, inside the declaration of class ch_stack, to just a function prototype and define push elsewhere. When we define it, we write the name out fully using the scope resolution operator. In this case, the function is not implicitly inline.

const int max_len = 40;
class ch_stack {
public:
   void  reset() { top = EMPTY; }
   void  push(char c);
   char  pop() {
      assert(top!= EMPTY);
      return s[top--];
   }
   char  top_of() {
      assert(top!= EMPTY);
      return s[top];
   }
   bool  empty()
     { return (top == EMPTY); }
   bool  full()
     { return (top == FULL); }
private:
   char  s[max_len]; 
   int   top;
   enum { EMPTY = -1, FULL = max_len - 1 };
};



void ch_stack::push(char c) //not inline { 
assert(top != FULL); 
top++; s[top] = c; 
} 

External Member Function - Exercise

Click the Exercise link below to rewrite the person class so it uses an external member function to print out its member data.
External Member Function - Exercise