HashMap<int[],string>通过考虑它们的值来映射整数数组 [英] HashMap<int[],string> mapping integer array by considering their values

问题描述

Given the following code, I get a null (what I want is "1234"). But I wish to have a map that could consider the key as equals, if the contents of int[] are equals (rather than consider that the references of int[]), how should I do it?

HashMap<int[], String> maps=new HashMap<int[], String>();
int[] i=new int[]{1,2,3};
int[] j=new int[]{1,2,3};
maps.put(i,"1234");
System.out.print(maps.get(j));

I am opened to any map that allows keeping int[] as the key (including TreeMap) and so on, with the side condition that if that does not hamper on the effectiveness of the map accessing time.

解决方案

No way to do that with arrays, because they don't override equals() and hashCode(). You should define your own class wrapping the array, which would override equals() and hashCode() or use a List<Integer> as key instead.

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