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HashMap 初始容量计算方法如果在new HashMap的时候，没有指定初始initialCapacity，则初始initialCapacity为16，负载因子为0.75，下次扩容阈值为 16*0.75=12这个初始容量不一定等于初始化完成后底层数组实际的容量，因为存在阈值的计算，方法如下；...

Java HashMap 的中 key 的哈希值是如何计算的，为何这么计算？

首先，我们知道 HashMap 的底层实现是开放地址法 + 链地址法的方式来实现。即数组 + 链表的实现方式，通过计算哈希值，找到数组对应的位置，如果已存在元素，就加到这个位置的链表上。在 Java 8 之后，链表过长还会转化为红黑树。这个数组并不是一开始就很大，而是随着 HashM...

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更新时间 2024-02-24 09:30:08

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