Sort ArrayList A based on ArrayList B

Question

Say for example I have:

ArrayList A; with values: "a","b", "c", "d", "e"

ArrayList B ; with values: "3","1", "5", "2", "4"

Then I performed

Collections.sort(B);

so then ArrayList B becomes:

"1","2", "3", "4", "5"

Now I want to sort ArrayList A based on the sort in ArrayList B , I should get ArrayListA :

"b","d", "a", "e", "c"

How can I achieve that? Sorry I'm still new to Android. Any help would be appreciated.

Answer 1

Just put the data into the TreeMap (which is a map sorted by natural ordering of its keys) and you're done.

Manual approach (if you want some programming practice) would be:

• put both lists in a single map where keys come from list B and values from list A
• get the keys from map and sort them
• iterate over sorted keys and get values from the map and put them into new list.

As you can see this question has nothing to do with Android, it's just a simple programming task.