True!

I thought the same, but i written an more extensive code , because i'm dosnt understood indexOf method. Now i understand it and i have more power xd

This looks very inefficient.

I love this solution

nice!

You shouldn't need to do this.species = ..., this.legs = ... etc in the Shark, Dog and Cat Classes. By calling super the parent class (Animal) is setting these properties for you.

i do not know the meaning of that word before,,,,,,,,,
sorry,,,,,
it is my mistake.

Its a typo, english is not his first language. He's my student.

I don't know if this is specifically what you were referring to when you commented on naming, but... wow, the name of that second function is REALLY rude where I come from.

I want you to spend a little more time deciding on how to name things. Also your indentation/code formatting could be much better! These things are important

nice solution!