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  1. #1
    aisha05 is offline Member
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    Default sorting a hash map without creating a new treemap

    Hi all,
    I have following questions:
    1)Is there any other way to sort a hashmap(based on key ordering) without using treemap?
    2)IF there is a way to sort a hashmap without creating a new instance of treemap,so it is consume lots of time as compare to sorting it with creating a new of treemap??

    Please help me to solve my puzzle.
    Thanks in advance:
    (happy):

  2. #2
    Junky's Avatar
    Junky is offline Grand Poobah
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    Sorting a Map makes no sense. Key/Value pairs are placed into a Map based on their hash not a particular order.

  3. #3
    aisha05 is offline Member
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    Dint get you junky.

    But i want to sort my hashmap.

  4. #4
    JosAH's Avatar
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    Quote Originally Posted by aisha05 View Post
    Hi all,
    I have following questions:
    1)Is there any other way to sort a hashmap(based on key ordering) without using treemap?
    2)IF there is a way to sort a hashmap without creating a new instance of treemap,so it is consume lots of time as compare to sorting it with creating a new of treemap??
    You can store the keys of your Map in an ArrayList and sort that collection, but I'd store everything in a TreeMap right away.

    kind regards,

    Jos
    cenosillicaphobia: the fear for an empty beer glass

  5. #5
    aisha05 is offline Member
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    so is it impact any performance time ??

  6. #6
    JosAH's Avatar
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    Quote Originally Posted by aisha05 View Post
    so is it impact any performance time ??
    Erm, yes; the sorting is as fast as can be but, as I wrote, why not stick your entries in a TreeMap in the first place?

    kind regards,

    Jos
    cenosillicaphobia: the fear for an empty beer glass

  7. #7
    aisha05 is offline Member
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    ohh. so it means if i stored my map in treemap so it is much faster than sorting its key??

  8. #8
    JosAH's Avatar
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    Quote Originally Posted by aisha05 View Post
    ohh. so it means if i stored my map in treemap so it is much faster than sorting its key??
    No, storing n entries in a HashMap takes O(n) steps; storing them in a TreeMap takes O(n*2log(n)) steps; sorting n items also takes O(n*2log(n)) steps. So, as I wrote, store those entries in a TreeMap in the first place.

    kind regards,

    Jos
    cenosillicaphobia: the fear for an empty beer glass

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