HashMap supports an array, then why is it disordered

Question

I read that the HashMap has a support array where records are stored (marked with a bucket number, initial size 16). Arrays are ordered, and I can call get (n) to get the element at the nth position. Then why the HashMap is unordered and does not have a get (n) method?

Answer 1

It depends on your idea of ​​what orderly means.

It is true HashMapsinternally to use an array or another set that has a fixed order . However, the order has nothing for the insertion order or something like that. Elements are ordered, for example, by increasing the size of the hash values , and they have nothing to do with the actual ordering of the elements themselves.

So it HashMapreally has something like a method get(n)if you think that nis the hash value of the key element. The method is called get(*key*), and it first calculates the hash-value of the given key element, and then looks at the value in the internal structure using get(*hash-value*)it.

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Answer 2

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