CODEWITHSUNDEEP
javahashmapkey-value
user2623946
user2623946

Reputation: 55

Remove stop words from a hashmap

I have a hashmap consisting of keys as words ( strings) and values as their counts ( integer).

I have to remove stopwords from the hashmap. Essentially , I have to do a hMap.remove("then") , hMpa.remove("where") for some 67 words. Is there any easier way of doing it ? Can I delete multiple keys from a hashmap in a single stroke.

Upvotes: 0

Views: 891

Answers (3)

JNL
JNL

Reputation: 4713

The following should help you out;

Map<String, Integer> ohm = new HashMap<String, Integer>();
List<String> al = new ArrayList<String>();
al.add("One");
al.add("Two");

ohm.put("One", 1);
ohm.put("Two", 2);
ohm.put("Three", 3);

ohm.keySet().removeAll(al);
System.out.println(ohm);  // Output: [Three = 3]

Hope this helps.

Upvotes: 1

pL4Gu33
pL4Gu33

Reputation: 2085

@user2623946 No, you must use a collection for it. Or something like that:

String[] arr = {"a","b","c"};
myMap.keySet().removeAll(Arrays.asList(arr));

Upvotes: 2

kiheru
kiheru

Reputation: 6618

Use hMap.keySet().removeAll(the_stuff_you_want_to_remove)

From the documentation:

The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations.

Upvotes: 5

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