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Thread: Question on HashMap internal implementation

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    Default Question on HashMap internal implementation

    HashMap internally uses Array and LinkedList to store the key value pairs. Can someone give detailed view of how exactly they are stored.


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    Default Re: Question on HashMap internal implementation

    Did you try google? Don't come up here with questions like, how to do this? How it works? How can i do this?
    As google can explain you this in detail.

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    Default Re: Question on HashMap internal implementation

    Have tried google. Didn't get clear answer for my above qn. Thats the reason for posting the same.

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    Default Re: Question on HashMap internal implementation


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    Default Re: Question on HashMap internal implementation

    Start at the source

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    Default Re: Question on HashMap internal implementation

    Copeg,

    Hashmap.jpg

    W.r.t image attached
    Each node in the linked lists stores a pairing of a key with a value. Now, to look for the mapping for, say, Ireland, we first compute this key's hash code (in this case, the string length, 7). Then we start traversing the linked list at position 7 in the table. We traverse each node in the list, comparing the key stored in that node with Ireland. When we find a match, we return the value from the pair stored in that node (Dublin). In our example here, we find it on the second comparison. So although we have to do some comparisons, if the list at a given position in the table is fairly short, we'll still reduce significantly the amount of work we need to do to find a given key/value mapping.

    Each Linked list node stores a value and link to the next node. My question is if "key" (of hashmap) is stored as value and second portion of node has link to the next node, where the exact object is stored which is paired with key of hashmap?

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    Default Re: Question on HashMap internal implementation

    You can see How HashMap works in Java an interesting article.

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