如何将键盘按下转换为 Java 程序中的值？

Question

In a text adventure game written in Java, I want the character race to be as follows( the number corresponds to the key the user types):

   // Character Race
    
    // 1) Human
    // 2) Dwarf
    // 3) Elf
    // 4) Orc

How do I write that out to the player?

Like this? So I ask the user which race they want:

    System.out.print("Enter character race: ");
    charRace = input.nextInt();
    System.out.println("Your character's race is " + charRace);

How do I tell my program that 1 = Human, 2 = Dwarf, etc...??

Do I need to create a dictionary or something similar?

Thanks!

Answer 1

You could just use some if statements to identify the entered race. Something like this

if(charRace == 1){
            String race = "Human";
        } else if(charRace == 2){
            String race = "Dwarf";
        } else if(charRace == 3){
            String race = "Elf";
        } else{
            String race = "Orc";
        }

Maybe not the most efficient way to do this though.

Answer 2

This might be a little out of the range of scope, but for me, when you have a limited range of possible values, I'd tend to look towards using a enum

enum Race {
    HUMAN(1), DWARF(2), ELF(3), ORC(4);
    
    private int value;

    private Race(int value) {
        this.value = value;
    }

    public int getValue() {
        return value;
    }
    
    public static Race from(int value) {
        for (Race race : Race.values()) {
            if (race.getValue() == value) {
                return race;
            }
        }
        return null;
    }
    
}

Then you can do fun things like...

Race race = Race.from(1);
if (race == null) {
    System.out.println("Invalid selection");
} else {
    switch (race) {
        case DWARF:
            System.out.println("Gunghrim Dwarf!");
            break;
        case ELF:
            System.out.println("Welcome Elf!");
            break;
        case HUMAN:
            System.out.println("Welcome Human!");
            break;
        case ORC:
            System.out.println("Welcome Orc!");
            break;
    }
}

You could even automate the menu. Start by adding something like...

public String getProperName() {
    StringBuilder sb = new StringBuilder(32);
    String name = name();
    sb.append(name.charAt(0));
    sb.append(name.substring(1).toLowerCase());
    return sb.toString();
}

to the Race enum and then you could create a menu doing something like...

List<Race> races = Arrays.asList(Race.values());
races.sort(new Comparator<Race>() {
    @Override
    public int compare(Race o1, Race o2) {
        return o1.getValue() - o2.getValue();
    }
});
for (Race race : races) {
    System.out.println(race.getValue() + ") " + race.getProperName());
}

which prints

1) Human
2) Dwarf
3) Elf
4) Orc

Have a look at the enums type trail for more details

Answer 3

If you are just using integers wouldn't a simple Array be the better choice?

String races[] = {"Dwarf","Elf","Human","Orc"};
System.out.println("You selected: "+races[charRace]);

edit:
If you want error handling:

String races[] = {"Dwarf","Elf","Human","Orc"};
if(charRace>=0&&charRace<races.length)
    System.out.println("You selected: "+races[charRace]);
else
    System.out.println("Error: invalid input!");

Also it is definetely more efficient to use a switch case over an if-else!
Here is an example, althought I dont recommend it since you are handling integers!!

    switch (charRace) {
        case 1:
            System.out.println("You selected Dwarf");
            break;
        case 2:
            System.out.println("You selected Elf");
            break;
        case 3:
            System.out.println("You selected Human");
            break;
        case 4:
            System.out.println("You selected Orc");
            break;
        default:
            System.out.println("Error: invalid input!");
            break;
    }

Answer 4

If you want this program more sustainable, you should use inherithence.

Like:

public class Orc extends Race{
}

public class Human extends Race{
}

After creation of the all races, you can create a method for creating new race for given number. For example:

public static Race createRace(int raceType){
  if(raceType == 1)
    return new Orc();
  else if(raceType == 2)
    return new Human();
}

Also, you can define different variables and different methods for your races.