hashCode() and equals() method override example

HashCodeExample.java

package problems.DataStructuresImpl;

import java.util.Objects;

class HashCodeExample {
   private String string;
   private int id;

   public HashCodeExample(String string, int id) {
      this.string = string;
      this.id = id;
   }

   @Override
   public boolean equals(Object o) {
      if (this == o)
         return true;
      if (o == null || getClass() != o.getClass())
         return false;
      HashCodeExample that = (HashCodeExample) o;
      return id == that.id && Objects.equals(string, that.string);
   }

   @Override
   public int hashCode() {
      return Objects.hash(string, id);
   }
}

//Test class
class Test
{
   public static void main (String[] args)
   {

      //Objects of HashCodeExample class.
      HashCodeExample example1 = new HashCodeExample("abc123", 1);
      HashCodeExample example2 = new HashCodeExample("abc123", 1);

      // comparing Objects hashCode
      if (example1.hashCode() != example2.hashCode()) {
         System.out.println("Both Objects are not equal.");
         return;
      }

      // Now, hashCode's are equal let's compare the objects itself
      if (!example1.equals(example2)) {
         System.out.println("Both Objects are not equal.");
         return;
      }

      System.out.println("Both Objects are equal.");
   }
}