Nulls & Null Objects

Excessive null checking can be alleviated by the use of the Null Object Pattern. Rather than passing a null value a object that represents the null state can be provided with sensible values.

Example

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  public interface Animal {
      void makeSound();
  }

  public class Dog implements Animal {
      public void makeSound() {
          System.out.println("woof!");
      }
  }

  public class NullAnimal implements Animal {
      public void makeSound() {

      }
  }

References

Null Object