get index number of specific key value

I have an ArrayList:

ArrayList

[doc_count=1439, count=value=689593.0, key=a, doc_count=1439, count=value=405340.0, key=b]

I am trying to use indexOf or stream to get the index number of key=a but I can't.

indexOf

stream

key=a

Is there any idea about this?

Do you have a JSON array? If not, then can you show us exactly what is stored in your array list?
– Tim Biegeleisen
Aug 22 at 8:29

Iterate using indices and check the elements. If the element at the current index fits your requirements (i.e. has key=a) then return that index. If you reach the end of the array without finding a correct element you don't have an index (which might be indicated by returning -1).
– Thomas
Aug 22 at 8:31

key=a

Tell exactly what you're using and provide some of the not working code.
– jle
Aug 22 at 8:32

1 Answer
1

Using java stream to get index number, you can use IntStream.range():

IntStream.range()

//Assume your list variable: myList OptionalInt IntStream.range(0, myList.size()) .filter(i -> "a".equals(myList.get(i).getKey())) .findFirst();

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