C ++：对“ f”中非成员类型“ Foo *”的成员“ Foo”的错误请求

Question

I know that this question has been asked before. I've tried implementing the answers, but am still running up against this error. If anyone has any advice, it would be greatly greatly appreciated. Below is the main file, the header file, and source file. Please let me know if you require any additional information. Thanks!

main.cpp

/* 
 * File:   main.cpp
 * Author: agoodkind
 *
 * Reads in a .list file from IMDB
 * Prompts user for Actor or Movie lookup
 * Iterates through file
 * Returns results of query
 * 
 */

#include <cstdlib>
#include <iostream>
#include <fstream>
#include <string>

#include "ActorResume.h"

using namespace std;


// function prototypes
void printmenu(void);
void createMovieList(fstream &infile);
void movieCastLookup(void);
void costarLookup(ActorResume &, fstream &infile);

int main() {    

    char choice;                //user menu selection
    bool not_done = true;       // loop control flag

    // create input file stream
    fstream infile;
    // CHANGE BACK TO NON-TEST!! 
    infile.open("/Users/agoodkind/Documents/CUNY/Analysis_and_Design/Assignments/Assignment1/actorsTEST.2010.list", ios::in);


    do {
        printmenu();
        cin >> choice;
        switch(choice)
        {
            case 'q':
            case 'Q':
                infile.close();
                not_done = false;
                break;
            case 'a':
            case 'A':
                createMovieList(infile);
                break;
            case 'm':
            case 'M':
                movieCastLookup();
                break;
            default:
                cout << endl << "Error: '" << choice << "' is an invalid selection -  try again" << endl;
                break;
        } //close switch

    } // close do() loop

    // exit program
    while (not_done);
    return 0;
} // close main()

/* Function printmenu()
 * Input:
 *  none
 * Process:
 *  Prints the menu of query choices
 * Output:
 *  Prints the menu of query choices
 */
void printmenu(void) {
    cout << endl << endl;
    cout << "Select one of the following options:" << endl;
    cout << "\t****************************" << endl;
    cout << "\t    List of Queries         " << endl;
    cout << "\t****************************" << endl;
    cout << "\t     A -- Look Up Actors' Costars" << endl;
    cout << "\t     M -- Movie Cast List" << endl;
    cout << "\t     Q -- Quit" << endl;
    cout << endl << "\tEnter your selection: ";
    return;    
}

/* Function costarLookup()
 * Input:
 *      Actor name
 * Process:
 *      Looks up all actors also in actor's movieList
 * Output:
 *      Prints list of costars
 */
void createMovieList(fstream &infile) {

    string actorName; // actor's name to be queried

    cout << endl << "Enter Actor Name: ";
    cin >> actorName;

    ActorResume *ar = new ActorResume(actorName);

    // add movie list to ActorCostars ADT created above
    // string for readline()
    string line;

    if (infile.is_open()) { //error checking to ensure file is open
        infile.seekg(0, ios::beg); // to be safe, reset get() to beginning of file
        while (infile.good()) { //error checking to ensure file is being read AND not end-of-file

            bool actor_found = false; // checks if actor name has been found
            getline(infile,line);

            if (line == actorName) {
                actor_found = true;
            }

            // add movies to actor's movieList
            while (actor_found && line[0] == '\t') {
                ar.addMovie(line);
            } 
        }
    }

    costarLookup(*ar, infile);
    delete ar;

} // close costarLookup()


void costarLookup(ActorResume actRes, fstream &infile) {

    // string for readline()
    string line;

    // vector to store costar names
    vector<string> costars;

    if (infile.is_open()) {             // error checking to ensure file is open

        infile.seekg(0, ios::beg);      // reset get() to beginning of file
        while (infile.good()) {         // error checking to ensure file is being read AND not end-of-file

            // while looping through file, store each actor's name
            string actorName;

            getline(infile,line);

            // check if first character is an alphanumeric character
            if (line[0] != '\t' && line[0] != NULL) {
                actorName = line;
            }

            // add actors name to list of costars
            if (actRes.movieInList(line)) {
                costars.push_back(actorName);
            }
        }
    }
    if (costars.size() == 0) {
        cout << "No costars found";
    }
    else if (costars.size() > 0) {
        cout << "Costars of " << actRes.getActorName() << ": " << endl;
        for (int i = 0; i < costars.size(); i++) {
            cout << "* " << costars[i];
        }
    }
}

ActorResume.h

/* 
 * ActorResume Specification Class
 */

#ifndef ACTORRESUME_H
#define ACTORRESUME_H

#include <iostream>
#include <string>
#include <vector>
#include <cstring>

using namespace std;

// ActorResume declaration
class ActorResume {

private:
    string actorName;
    vector<string> movieList;

public:

    //default constructor
    ActorResume() {
//        actorName = NULL;
        movieList.clear();
    }

    //typical constructor implemented for creating ActorResume
    ActorResume(string aName) {
        actorName = aName;
        movieList.clear();
    }

    // member functions
    void addMovie(string);
    string getActorName();
    bool movieInList(string);
//    void printMovieList();

};


#endif  /* ACTORRESUME_H */

ActorResume.cpp

// ActorResume Implementation

#include <iostream>
#include <string>
#include <vector>
#include <cstring>

#include "ActorResume.h"

/*
 * ActorResume function addMovie()
 * Input:
 *      Movie Name
 * Process:
 *      adds movie to movieList
 * Output:
 *      None
 */
void ActorResume::addMovie(string movie) {
    movieList.push_back(movie);
//    return;
}

/*
 * ActorReusme function getActorName()
 * Input:
 *      None
 * Process:
 *      returns actor's name
 * Output:
 *      String of actor's name
 */
string ActorResume::getActorName() {
    return actorName;
}

/*
 * ActorResume function movieInList()
 * Input:
 *      string to search for
 * Process:
 *      searches movieList vector for string
 * Output:
 *      If movie is found, true
 *      Else, false
 */
bool ActorResume::movieInList(string movie) {
    for(size_t i = movieList.size() - 1; i != (size_t)-1; i--) {
        if (movieList[i] == movie) {
            return true;
        }
    }
    return false;
}

Error:

main.cpp: In function 'void createMovieList(std::fstream&)':
main.cpp:124: error: request for member 'addMovie' in 'ar', which is of non-class type 'ActorResume*'

Answer 1

Error request for member 'Foo' in 'f', which is of non-class type 'Foo*'

The error tells you all you need to know.

ActorResume *ar = new ActorResume(actorName);

ar is a pointer to an ActorResume object, not an ActorResume object in and of itself. So...

ar.addMovie(line);

Should be

ar->addMovie(line);

You use the -> operator to derefence a pointer and access members of the object it refers to, not the dot operator. A pointer has no members.