Getting an instance of class X from ArrayList of class X out of position
If I have ArrayList
in Java 6 program:
ArrayList<Keyword> = new ArrayList<Keyword>();
Where a Keyword
has int keywordNo
, String text
, int frequency
and a few other fields.
How do I get an item from ArrayList
if I know keywordText
but not the item's position or field value keywordNo
?
I know that I could use a loop and just read the ArrayList
comparison Strings
until I find the item, but is there any better alternative?
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You will need to iterate over each item in the list using a loop. For each iteration, you will need to get the current element and check its value.
For faster access, you should use Map<String, Keyword>
where String is the Text keyword.
You can place your keywords on the map like this:
Map<String, Keyword> keywordsMap = new HashMap<String, Keyword>();
for (Keyword k : keywordList) {
keywordsMap.put(k.text, k);
}
Then, if you want to access a specific keyword, you can make a call like this:
Keyword result = keywordsMap.get("somekeyword");
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