无法在 if 语句之外访问 c++ 结构

Question

目标是让用户输入两部电影的一些电影信息。
然后两个函数输出电影数据
问题是当我尝试使用 if 语句之外的函数时，它们无法再被访问。

#include <iostream>
#include <string>
using namespace std;

struct MovieData // the stuct
{
    string Title,  // required varibles
        Director;
    int yearReleased,
        runTime;

    MovieData(string TITLE, string  DIRECTOR, int YearReleased, int RunTime)  // constructors 
    {
        Title = TITLE;
        Director = DIRECTOR;
        yearReleased = YearReleased;
        runTime = RunTime;
    }
    string getTitle() // getters
    { return Title; }
    string getDirector()
    { return Director; }
    int getYear()
    { return yearReleased; }
    int getLength()
    { return runTime; }
};

void printMovie1(MovieData movieprint1) // fucntion that outputs movie 1
{
    cout << "Title of movie " << movieprint1.getTitle() << endl;
    cout << "Director is " << movieprint1.getDirector()<< endl;
    cout << "Movie release year " << movieprint1.getYear()<< endl;
    cout << "Movie length " << movieprint1.getLength() << endl;
}

void printMovie2(MovieData movieprint2) // function that outputs movie 2
{
    cout << "Title of movie " << movieprint2.getTitle() << endl;
    cout << "Director is " << movieprint2.getDirector() << endl;
    cout << "Movie release year " << movieprint2.getYear() << endl;
    cout << "Movie length " << movieprint2.getLength() << endl;
}

int main()
{
    string Title, // local varibles
        Director;
    int yearReleased,
        runTime;

    for (int i = 0; i < 2; i++) // forward loop to enter movie info
    {
        cout << "Please enter the movie " << (i + 1) << " title ";
        getline(cin, Title);

        cout << "Now the director ";
        getline(cin, Director);

        cout << "What year was " << Title << " releasted ";
        cin >> yearReleased;

        cout << "Lastly the length ";
        cin >> runTime;
        cin.ignore();

        if (i == 0)
        {
            MovieData movie1(Title, Director, yearReleased, runTime);
            // I know function works when placed here
            // printMovie1(movie1); 
        }
        else if (i == 1)
        {
          MovieData  movie2(Title, Director, yearReleased, runTime);
         // I know function works when placed here
          // printMovie2(movie2);
        }
    }
    // these functions now dont work
    enter code hereprintMovie1(movie1);
    printMovie2(movie2);
    return 0;
}

Answer 1

您的 MovieData 仅存在于括号范围内。一旦退出外部范围，就无法再访问它。您可以修复它，在范围之外声明您的变量。

    MovieData  movie; //default construction
    if (i == 0)
    {
        movie = MovieData(Title, Director, yearReleased, runTime);
        // I know function works when placed here
        // printMovie1(movie1); 
    }
    else if (i == 1)
    {
      movie= MovieData(Title, Director, yearReleased, runTime);
     // I know function works when placed here
      // printMovie2(movie2);

    }
    //you can now use movie