Question about filtering Multidimensional Arrays (challenge 13)


#1

Hi all!

So, does the filter function not automatically filter every entry in a multidimensional array? Do I need to loop it through every single row?

Does this: var filteredRocks = GRID.filter(function(cell) {return cell === “^”}); only do a single row?

I don’t think I’m really understanding what’s going on here. Aaaaaahhh


#2

Hi @Kurtillius. Look up some of the previous threads about challenge 13. Like this one:

Most participants (including me) completed the challenge using a loop, not a filter. But there is an ingenious person in that thread who used filter successfully by creating a new array of all coordinates first. And there might be some other successful strategies if you look through other threads.


#3

To go on what @RebelBeckerton mentioned, think first what you’re given (a 2D array) and what you want the output to be (a 1D array of all the rocks). I left a link to an article in the forum post ‘Challenge 13 Filter’ and would highly recommend reading it. It gave me the insight I needed to complete Challenge 13 using the ‘map’, ‘reduce’ and ‘filter’ functions that JavaScript provides. If you have any questions, feel free to ask!


#4

Thanks, team! I’ll take another look when I’m home from work