java - Removing item from ArrayList using remove(<index>) or remove(<objectRef>) -

i want create program displays current staff in arraylist before asking user input of payroll number they'd remove. user should input payroll number of 1 of 3 staff members , press enter. upon pressing enter, program should remove particular staff member array list , display entire list again (missing out staff member they've deleted obviously). if user no longer wishes remove payroll numbers, payroll number entry should 0 , should display contents of list again.

the problem i'm having remove part.

i've been recommended of 2 ways of achieving this:

this 'search' method should return either position within arraylist (so remove(<index>) may used) or reference object (so remove(<objectref>) may used). if staff member not found, search method should return -1 (if remove(<index>) being used) or null (if remove(<objectref>) being used).

however not sure how implement in java.

here file structure:

arraylisttest.java

import java.util.*;  import personnelpackage.personnel;  public class arraylisttest {     static scanner keyboard = new scanner(system.in);      public static void main(string[] args)     {         long searchquery;          arraylist<personnel> stafflist = new arraylist<personnel>();         personnel[] staff =             {new personnel(123456,"smith","john"),              new personnel(234567,"jones","sally ann"),              new personnel(999999,"black","james paul")};          (personnel person:staff)             stafflist.add(person);                  {             showdisplay(stafflist);              system.out.print("\nplease enter payroll number search: ");             searchquery = keyboard.nextlong();              searchforpayrollnumber(stafflist, searchquery);           }while(!(searchquery == 0));       }      private static void showdisplay(arraylist<personnel> stafflist)     {         system.out.print("\n------------- current staff list -------------\n");         (personnel person : stafflist)         {             system.out.println("payroll number: " + person.getpaynum());             system.out.println("surname: " + person.getsurname());             system.out.println("first name(s): " + person.getfirstnames() + "\n");         }     }      public static void searchforpayrollnumber(arraylist<personnel> stafflist, long searchquery)     {         long index = stafflist.indexof(searchquery);;          (personnel person: stafflist)         {             if (person.getpaynum() == searchquery)             {                                system.out.print("\n------------- staff member found , removed! -------------");                 system.out.println("\n\nfirst name(s): " + person.getfirstnames());                 system.out.println("\nsurname: " + person.getsurname());                 system.out.print("\n-----------------------------------------------");                  stafflist.remove(index);                 return;             }         }          system.out.print("\n------------- no staff members found. program terminated -------------");         return;      }  } 

personnel.java (in own package named personnelpackage)

package personnelpackage;  public class personnel {     private long payrollnum;     private string surname;     private string firstnames;      public personnel(long payrollnum, string surname, string firstnames)     {         this.payrollnum = payrollnum;         this.surname = surname;         this.firstnames = firstnames;     }      public long getpaynum()     {         return payrollnum;     }      public string getsurname()     {         return surname;     }      public string getfirstnames()     {         return firstnames;     }      public void setsurname(string newname)     {         surname = newname;     } } 

public static long searchforpayrollnumber(arraylist<personnel> stafflist, long searchquery) {     //long index = stafflist.indexof(searchquery);  for(int = 0; < stafflist.size(); i++) {     if (stafflist.get(i).getpaynum() == searchquery) {         system.out.print("\n------------- staff member found , removed! -------------");         system.out.println("\n\nfirst name(s): " + stafflist.get(i).getfirstnames());         system.out.println("\nsurname: " + stafflist.get(i).getsurname());         system.out.print("\n-----------------------------------------------");          //stafflist.remove(i);         return i;     } } system.out.print("\n------------- no staff members found. program terminated -------------"); return -1; }