Question

I’m trying to write code that will create multiple HashSets using a for loop. I’m trying to store occurrences of unique words based on their length. For example, a word of length 4 would go in HashSet A, while a word of length 20 would go in HashSet B. Instead of creating 16 HashSets manually, is there a way for me to use a for loop (int i=4; i<21; i++)? Thank you!

Answer 1

Rather than having 16 different HashSet‘s, you can have a Map<Integer, Set<String>>.

So, while adding, you can just test whether a key is already there or not. If a key is there, just add the word to the Set for that key, else add a new entry.

So, here’re the steps you need to follow: –

• Get the length of the word. Say length.

• Test if Map contains key length – Map#containsKey(Object)

• If length key is there, get the Set for that key – Map#get(Object). And add the word to that Set.

• If length key is not there, create a new HashSet, add the current word in it. And add a new entry in your Map with the current length as key – Map#put(K, V)