Question

I am splitting using

String[] arr = originalString.split(",");

Which is storing true, false, true and so on depending on what the user picked. How would I say just remove the false ones and leave the true values in the array?

Answer 1

• Using your existing method, iterate through the returned array, set ‘false’ Strings to null. This really doesn’t buy you much since you’re having to go through the array linearly and look at each element, which you could simply do when processing the responses. And since you can’t reduce the size of an array … you can’t really “remove” them in that sense. If you really need an array that contains only some of the responses, you’d need to copy the ones you want to a new array in this loop.

• Create a List from your array, remove items using its methods; the list will shrink and contain only what you want. Again … lots of linear traversing here, but you do end up with the result you’re looking for.

• Don’t use String.split() in the first place. If you’re not interested in ‘false’ responses, use a regex via Java’s Matcher class to extract only the ‘true’ respnonses from your original string.

• Change your approach. If these are user responses, don’t store them in a String. Create a Response object that stores the user input as well as what they were responding to. Store these in two Lists, one for “true” responses, one for “false” responses.