Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
this approach is not good because it will take so much process time
This answer was probably made before the introduction of let,const
This comment is hidden because it contains spoiler information about the solution
Very cool! Just learnt something new!
You can check whether an item exist or no in an array, by checking its index, so if the index ( == -1) OR in other way (< 0), it means that this item doesn't exist, so the logic here is to push this item to the output array.
why < 0 though?
I didnt know you can do that, very Cool!
nope
Is there a reason/efficiency of using a new Array constructor instead of just initalizating a array literal?