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.
Its kind of like acumulator and currentVlaue in most .reduce examples. I recomend going to the link below to find more information regarding the Array.prototype.reduce function. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce
I guess
previousValueandcurrentValue