How to compare objects by multiple fields

Question

Assume you have some objects which have several fields they can be compared by:

public class Person {

    private String firstName;
    private String lastN         


        

Answer 1

It is easy to compare two objects with hashcode method in java`

public class Sample{

  String a=null;
  String b=null;

  public Sample(){
      a="s";
      b="a";
  }
  public Sample(String a,String b){
      this.a=a;
      this.b=b;
  }
  public static void main(String args[]){
      Sample f=new Sample("b","12");
      Sample s=new Sample("b","12");
      //will return true
      System.out.println((s.a.hashCode()+s.b.hashCode())==(f.a.hashCode()+f.b.hashCode()));

      //will return false
      Sample f=new Sample("b","12");
      Sample s=new Sample("b","13");
      System.out.println((s.a.hashCode()+s.b.hashCode())==(f.a.hashCode()+f.b.hashCode()));

}