Calling a method using an array in java

If these two functions are not in the same class (or the class in which sortVehicles is declared is not a superclass of the one where this main method is declared), you will need to specify the name of the class in which sortVehicles is declared when calling the sortVehicles method, thusly:

VehicleSorter.sortVehicles(vehicles)

Alternatively, you may statically import the sortVehicles method in the class with your main method:

import static com.example.VehicleSorter.sortVehicles;

Alternatively, you can make main in your Vehicle class.

public class Vehicle
{
    public static void main(String[] args) throws Exception {
        Vehicle[] vehicles = fillArray(args[0]);

    vehicles = fillArray(args[1]);

    System.out.print("Enter 1 to print all of the files.\nEnter 2 to sort the files by email and print.\nEnter 3 to print the amount of files.\nEnter 4 to print only bike and truck files.\nEnter 5 to print only area codes (987).\nEnter number: ");

    Scanner input = new Scanner(System.in);

    int x = input.nextInt();

    while (true) {
        if (x == 1) {
            printAll(vehicles);
        } else if (x == 2) {
            sortVehicles(vehicles);
        } else if (x == 3) {
            printRecordNumber(vehicles);
        } else if (x == 4) {
            printBicyclesAndTrucks(vehicles);
        } else if (x == 5) {
            printByAreaCode(vehicles);
        }
    }

}// end main

public static void sortVehicles(Vehicle[] vehicles)
{
    Arrays.sort(vehicles);
    for(int i = 0; i < vehicles.length; i++)
    {
        System.out.println(vehicles[i]);
    }
    return;
}

}

• static methods should be called with <class name>.<function name> e.g. Math.max(int , int).

So here in your case it should be:

<Class name to which sortVehicles belongs>.sortVehicles(vehicles)

• else put the static method inside the class to which main method belongs:

  public class { public static void main(String[] args) throws Exception { Vehicle[] vehicles = fillArray(args[0]);

      vehicles = fillArray(args[1]);
  
      System.out.print("Enter 1 to print all of the files.\nEnter 2 to sort the files by email and print.\nEnter 3 to print the amount of files.\nEnter 4 to print only bike and truck files.\nEnter 5 to print only area codes (987).\nEnter number: ");
  
      Scanner input = new Scanner(System.in);
  
      int x = input.nextInt();
  
      while (true) {
          if (x == 1) {
              printAll(vehicles);
          } else if (x == 2) {
              sortVehicles(vehicles);
          } else if (x == 3) {
              printRecordNumber(vehicles);
          } else if (x == 4) {
              printBicyclesAndTrucks(vehicles);
          } else if (x == 5) {
              printByAreaCode(vehicles);
          }
      }
  
  }
  public static void sortVehicles(Vehicle[] vehicles)
  {
      Arrays.sort(vehicles);
      for(int i = 0; i < vehicles.length; i++)
      {
           System.out.println(vehicles[i]);
      }
      return;
  }
  
  }