“for loop”— and The Pain of Existence
Say you’ve got a bunch-a items in a list, [4, 1, 3, 2] for example. If you look at all the reasons you might be using for loops, you can probably break it down into one of the following. 1. Filter a specific sub-list from the list . For example we want to pull out all the items less than 3 , so that [4, 1, 3, 2] -> [1, 2] 2. Reduce the values into a single one . For example, we want to sum all the items on the list, so that [4, 1, 3, 2] -> 10 3. Map an operation onto each item on the list . For example, we want to double each item, so that [4, 1, 3, 2] -> [8, 2, 6, 4] . 4. Sort the list in some form . For example, in descending form, so that [4, 1, 3, 2] -> [4, 3, 2, 1] Oh there are many, many more things that you could be doing in your for loops, but the vast majority tends to fall into one of the above filter / reduce / map / sort buckets. Or, ...