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fuzhengweifuzhengwei
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小傅哥，文章代码更新。晚上好!
面经手册 · 第4篇《HashMap数据插入、查找、删除、遍历，源码分析》
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‎README.md

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2. [面经手册 · 第1篇《认知自己的技术栈盲区》](https://bugstack.cn/interview/2020/07/30/%E9%9D%A2%E7%BB%8F%E6%89%8B%E5%86%8C-%E7%AC%AC1%E7%AF%87-%E8%AE%A4%E7%9F%A5%E8%87%AA%E5%B7%B1%E7%9A%84%E6%8A%80%E6%9C%AF%E6%A0%88%E7%9B%B2%E5%8C%BA.html)
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3. [面经手册 · 第2篇《数据结构，HashCode为什么使用31作为乘数？》](https://bugstack.cn/interview/2020/08/04/%E9%9D%A2%E7%BB%8F%E6%89%8B%E5%86%8C-%E7%AC%AC2%E7%AF%87-%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84-HashCode%E4%B8%BA%E4%BB%80%E4%B9%88%E4%BD%BF%E7%94%A831%E4%BD%9C%E4%B8%BA%E4%B9%98%E6%95%B0.html)
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4. [面经手册 · 第3篇《HashMap核心知识，扰动函数、负载因子、扩容链表拆分，深度学习》](https://bugstack.cn/interview/2020/08/07/%E9%9D%A2%E7%BB%8F%E6%89%8B%E5%86%8C-%E7%AC%AC3%E7%AF%87-HashMap%E6%A0%B8%E5%BF%83%E7%9F%A5%E8%AF%86-%E6%89%B0%E5%8A%A8%E5%87%BD%E6%95%B0-%E8%B4%9F%E8%BD%BD%E5%9B%A0%E5%AD%90-%E6%89%A9%E5%AE%B9%E9%93%BE%E8%A1%A8%E6%8B%86%E5%88%86-%E6%B7%B1%E5%BA%A6%E5%AD%A6%E4%B9%A0.html)
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5. [面经手册 · 第4篇《HashMap数据插入、查找、删除、遍历，源码分析》](https://bugstack.cn/interview/2020/08/13/%E9%9D%A2%E7%BB%8F%E6%89%8B%E5%86%8C-%E7%AC%AC4%E7%AF%87-HashMap%E6%95%B0%E6%8D%AE%E6%8F%92%E5%85%A5-%E6%9F%A5%E6%89%BE-%E5%88%A0%E9%99%A4-%E9%81%8D%E5%8E%86-%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90.html)

‎interview-05/pom.xml

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<?xml version="1.0" encoding="UTF-8"?>
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<project xmlns="http://maven.apache.org/POM/4.0.0"
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
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<parent>
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<artifactId>interview</artifactId>
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<groupId>org.itstack</groupId>
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<version>1.0-SNAPSHOT</version>
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</parent>
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<modelVersion>4.0.0</modelVersion>
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<artifactId>interview-05</artifactId>
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</project>

‎interview-05/src/test/java/org/itstack/interview/test/ApiTest.java

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package org.itstack.interview.test;
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import org.junit.Test;
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import java.util.HashMap;
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import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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public class ApiTest {
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public static void main(String[] args) {
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System.out.println("");
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Map<String, String> map = new HashMap<String, String>();
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map.put("", "");
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map.get("");
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map.remove("");
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}
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@Test
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public void test_Iterator() {
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Map<String, String> map = new HashMap<String, String>(64);
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map.put("24", "Idx：2");
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map.put("46", "Idx：2");
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map.put("68", "Idx：2");
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map.put("29", "Idx：7");
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map.put("150", "Idx：12");
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map.put("172", "Idx：12");
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map.put("194", "Idx：12");
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map.put("271", "Idx：12");
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System.out.println("排序01：");
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for (String key : map.keySet()) {
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System.out.print(key + " ");
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}
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map.put("293", "Idx：12");
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map.put("370", "Idx：12");
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map.put("392", "Idx：12");
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map.put("491", "Idx：12");
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map.put("590", "Idx：12");
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System.out.println("\n\n排序02：");
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for (String key : map.keySet()) {
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System.out.print(key + " ");
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}
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map.remove("293");
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map.remove("370");
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map.remove("392");
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map.remove("491");
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map.remove("590");
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System.out.println("\n\n排序03：");
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for (String key : map.keySet()) {
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System.out.print(key + " ");
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}
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}
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@Test
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public void test_idx12() {
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for (int i = 1; i < 1000; i++) {
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String key = String.valueOf(i);
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int hash = key.hashCode() ^ (key.hashCode() >>> 16);
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int idx = (64 - 1) & hash;
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if (idx == 2) {
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System.out.println(i + " Idx：" + idx);
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}
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if (idx == 7) {
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System.out.println(i + " Idx：" + idx);
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}
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if (idx == 12) {
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System.out.println(i + " Idx：" + idx);
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}
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}
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/**
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* idx：12
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* 40
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* 51
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* 62
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* 73
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* 84
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* 95
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* 150
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* 161
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*
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* idx：2
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* 13
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* 24
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*
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* idx：7
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*
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* 18
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* 29
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* 90
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*/
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}
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}

‎pom.xml

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<module>interview-02</module>
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<module>interview-03</module>
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<module>interview-04</module>
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<module>interview-05</module>
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</modules>
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<dependencies>

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