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I know how to find the first element of a list by predicate: Find first element by predicate

Is there an easy way to get the index of that element?

pppery
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Roland
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  • This question is NOT a duplicate to https://stackoverflow.com/questions/23696317/java-8-find-first-element-by-predicate. Although answers to that question can be used to construct an answer to this one, there could also be answers which don't require iterating the stream. – Lii Feb 11 '22 at 13:23

1 Answers1

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If I understood correctly, that's the classic case where you need IntStream; but that would only apply for a List obviously. 

IntStream.range(0, yourList.size())
   .filter(i -> yourList.get(i)... your filter condition)
   .collect(Collectors.toList());
Eugene
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    If you really only want the first index, use `findFirst()` instead of `collect(...)`. This will only execute the filter until you find the first match. – Malte Hartwig Apr 25 '17 at 12:01