为什么此代码无法识别这两个变量相同？

Question

Hey I'm trying to take a String input from the user (in this case a name of a film eg Good Burger). I have an arraylist of class Film from which I'm iterating through. On each iteration a method in the instance of class Film is called which returns a String of the film name. When I'm comparing these two, it doesn't seem to recognise that they are equal and I can't figure out why.

Heres the code that's taking the input and comparing the two:

//Get the films input by the user.

    int numberOfFilmsCheck;
    numberOfFilmsCheck = 0;
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    Film tempFilm;
    System.out.println("Please enter the names of the films you wish to be in the new schedule");
    System.out.println("Press enter after each one.");

    while(numberOfFilmsCheck < numberOfFilms){
        boolean foundFilm;
        foundFilm = false;
        String inputFilmName = null;
        tempFilm = null;
        String filmName;
        filmName = null;
        try{
            inputFilmName = reader.readLine();
            System.out.println(inputFilmName);
        }
        catch (IOException e){
            System.out.println("Error");
        }

        for(Film film : films){
            film.printFilmName();
            if(inputFilmName.equals(filmName)){
                foundFilm = true;
                tempFilm = film;
                System.out.println("Found film name");
                break;
            }
        }

        if(foundFilm == true){
            newFilmsForSchedule.add(tempFilm);
            numberOfFilmsCheck++;
        }
        else{
            System.out.println("The film you entered has not been recognised.");
            System.out.println("Please enter the film name as shown above.");
        }

and here is the code in class Film that returns the film name:

public String getFilmName()
{
    return filmName;
}

If you notice any rogue print statements in there that's just me checking the code is working correctly.

Any help is much appreciated! Thanks

Answer 1

The getFilmName() function looks like quite a useful one, but only if you end up calling it :-)

You appear to set filmName to null at the start, then you never actually change it (by calling getFilmName() , for example). Hence, it will be null for the purposes of comparison.

I suspect you may need something like:

for(Film film : films){
    film.printFilmName();
    filmName = film.getFilmName();               // <-- Added this.
    if(inputFilmName.equals(filmName)){          // <-- So that this works.
        foundFilm = true;
        tempFilm = film;
        System.out.println("Found film name");
        break;
    }
}

Answer 2

Try putting this code:

System.out.println("'" + inputFilmName + "' vs '" + filmName + "'")

before the if(inputFilmName.equals(filmName)){ line and you WILL see why it is not equal. Oh notice the single quotes..