I have a map with strings as values. I want to sort it firstly by length, and if length of the strings is the same, i want to sort it alphabetic. I wrote those code :

String out=outMap.values().stream().sorted(Comparator.comparing(e -> e.length()).thenComparing()...).collect(Collectors.joining());

The problem is, when i am writing thenComparing, I couldn't use e.length() anymore. How can i fix it?

EDIT : Map<Character, String> . I want to sort the strings and make one string in output by concat all of them.

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  • What are the types of outMap?– BohemianFeb 14 at 21:04
  • fix what? what exactly is the problem?– EugeneFeb 14 at 21:05
  • Map<Character, String>– Anton BarinovFeb 14 at 21:08

How about

String out=outMap.values().stream().sorted(Comparator.comparing(String::length).thenComparing(Comparator.naturalOrder())).collect(Collectors.joining());
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  • 1
    Alternatively, (String e) -> e.length().– shmoselFeb 14 at 21:06
  • 2
    Comparator.comparingInt(String::length) .thenComparing(String.CASE_INSENSITIVE_ORDER); just in case.– boobalan gnanasekaranFeb 14 at 21:08
  • Yes, that works fine, thanks a lot– Anton BarinovFeb 14 at 21:11

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