I was checking out the solution to this challenge, to see if my intuition was right. It was, for the most part, except for one radical difference:
…function dropElements(arr, func) {
// drop them elements.
var times = arr.length;
for (var i = 0; i < times; i++) {
if (func(arr[0])) {
break;
} else {
arr.shift();
}
}
return arr;
}
// test here
dropElements([1, 2, 3, 4], function(n) {return n >= 3;})…
I wouldn´t have created the times variable at all, instead I would have just added “< arr.length” inside the for loop, as usual. I tried that, but it doesn´t work. I don´t really understand the difference between both of these. Could anyone explain?
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So follow the logic: Loop through the array a certain number of times, and, if the first element each time doesn’t return true from a given function, remove it.
Each time, we’re shortening the array, so arr.length will be changing. But we still may want to process through every element, so we assign arr.length to a variable before, so that it remains constant (thus the famous coder quote, “Variables won’t, constants aren’t.”)
If we used arr.length each time, that number will change. But i is going to increment, regardless – by using arr.length as it gets shorter and shorter, we would eventually have elements not getting hit.
If, instead, we used a do/while, we could simply remove elements and, while the arr.length && !func(arr[0]) values return true, keep removing the first element. That would have much the same end result, without the pesky i and the extra variable for times.
Did you read the test spec? It is NOT that you filter out all instances that pass, it is that you stop at the FIRST instance of pass and return the remaining elements.
It’s a challenge to give constructive hints without simply telling you what to do. There are a few ways this can be handled, but what it boils down to is this:
Does the first el return true from the passed func? If so, return the array as it stands.
If it doesn’t, remove that first element, and run step one again, as long as the array contains some elements.
If no elements return true, simply return an empty array.
