Java（eclipse）：如何从同一个项目中的另一个类调用int或string？

Question

How can I use an int or string from another class in same project, for example, here we go with a class called Estadisticas :

public class Estadisticas {

    public void stats() {

        final String c1 = "Tu personaje";
        final int Nivel = 1;
        final int Salud = 50;
        final int Ataque = 2;
        final int Defensa = 1;

        final String c2 = "Primer monstruo - Rata rabiosa";
        final int SaludM1 = 2;
        final int AtaqueM1 = 1; 

    }
}

And I want to know how to call for example the String c1 to println like this:

public class Start extends Estadisticas {
    public static void main() {
        System.out.println(String c1);
    }

}

After reading some example codes and people with similar problem, I tried with extends Estadisticas with no luck, and I'm putting this code as I don't know how to call that string from another class in same project.

Thanks in advance! Cristobal.

Answer 1

If you're trying to call a variable from another class, you have several options:

1) Declare the variable in the other class as static:

public class Estadisticas {

  public static String c1 = "Tu personaje";
  ...
}

So in the other class, you can just call the string like so:

public class Start extends Estadisticas {
  public static void main() {
    System.out.println(Estadisticas.c1);
  }
}

2) Have the stats method return the string:

public String stats() {

  final String c1 = "Tu personaje";
  final int Nivel = 1;
  final int Salud = 50;
  final int Ataque = 2;
  final int Defensa = 1;

  final String c2 = "Primer monstruo - Rata rabiosa";
  final int SaludM1 = 2;
  final int AtaqueM1 = 1; 

  return c1;
}

So you can do this:

public class Start extends Estadisticas {
  public static void main() {
    Estadisticas es = new Estadisticas();
    System.out.println(es.stats());
  }
}

3) Use an accessor method and instance variables:

public class Estadisticas {
  private String c1, c2;
  private int nivel, salud, ataque, defensa, saludM1, ataqueM1;

  public void stats() {
    c1 = "Tu personaje";
    nivel = 1;
    salud = 50;
    ataque = 2;
    defensa = 1;

    c2 = "Primer monstruo - Rata rabiosa";
    saludM1 = 2;
    ataqueM1 = 1; 
  }

  //accessor method
  public String getc1() {
    return c1;
  }
}

So in the other class you can use:

public class Start extends Estadisticas {
  public static void main() {
    Estadisticas es = new Estadisticas();
    System.out.println(es.getc1());
  }
}

Answer 2

Like this :

public class Estadisticas {
    final String c1 = "Tu personaje";
    final int Nivel = 1;
    final int Salud = 50;
    final int Ataque = 2;
    final int Defensa = 1;

    final String c2 = "Primer monstruo - Rata rabiosa";
    final int SaludM1 = 2;
    final int AtaqueM1 = 1; 

    public void stats() {

    }
}

public class Start extends Estadisticas {
    public static void main() {
     Estadisticas  es = new Estadisticas (); // create instance here
        System.out.println(es.c1);  // print using the instance


    }

}

Answer 3

this is public example. In java you need to use them as private for security.

public class Estadisticas {
                public String c1 = "Tu personaje";
                public int Nivel = 1;
    }

This is calling from another class.

    public class Start {
        public static void main() {

            Estadisticas.Nivel;
            Estadisticas.c1 ;
        }
  }