如何在另一个 class 中使用公共方法

Question

I have a class named PointOfSale which have a public method getTpid, but I failed when I want to call this method in my main class, I can only call "TPID_FIELD_NUMBER", how to solve this problem?

PointOfSale ps = new PointOfSale();
ps.TPID_FIELD_NUMBER; //correct
ps.getTpid();// error

public final class PointOfSale implements PointOfSaleOrBuilder {
   public static final int TPID_FIELD_NUMBER = 1;
   private int tpid_;

  @java.lang.Override
  public int getTpid() {
    return tpid_;
  }
}

public interface PointOfSaleOrBuilder {
  
  int getTpid();

}

Answer 1

public static void main(String[] args) {
     PointOfSale ps = new PointOfSale();
     ps.getTpid();
}

Answer 2

I think that you just need to add () at the end of your call.

ps.TPID_FIELD_NUMBER is a call for a constant. If you want to call a method, you should call like this: ps.getTpid();

Answer 3

The issue is with the line "ps.TPID_FIELD_NUMBER;". This will give "Not a statement" error. You should assign it to a variable for successful execution.

Your code should look like,

public static void main(String[] args) {
    PointOfSale ps = new PointOfSale();
    int num = ps.TPID_FIELD_NUMBER; 
    ps.getTpid();
}