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If Else or Switch Case to Polymorphism

If you try to express your logic in if-else way like this,

  private static String getSoundIfElseWay(String animal) {
       if (animal.equalsIgnoreCase("Dog"))
            return "Bark";
       else if (animal.equalsIgnoreCase("Cat"))
            return "Mew";
       else if (animal.equalsIgnoreCase("Lion"))
            return "Roar";
       return "";
  }

then polymorphic way would be,

 private static String getSoundPolymorphicWay(Animal animal){
      return animal.say();
 }

public abstract class Animal {
      public abstract String say();
 }

 public class Dog extends Animal{
      @Override
      public String say() {
           return "Bark";
      }
 }

 public class Cat extends Animal {
      @Override
      public String say() {
           return "Mew";
      }
 }

 public class Lion extends Animal {
      @Override
      public String say() {
           return "Roar";
      }
 }

Look at the change in behavior based on the condition. If you could come up with a object than could take this behavior, push that to the corresponding object.

Same rule applies to switch-case also.

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