From 1458e0aefd6f254c4c9377994b3ec72c1ea6e0aa Mon Sep 17 00:00:00 2001
From: andyoung <1218853253@qq.com>
Date: Wed, 26 Jul 2023 14:52:22 +0800
Subject: [PATCH] Update hashmap-source-code.md
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

添加HashMap示例,加深对HashMap理解
---
 docs/java/collection/hashmap-source-code.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/docs/java/collection/hashmap-source-code.md b/docs/java/collection/hashmap-source-code.md
index 8877a451..8c165756 100644
--- a/docs/java/collection/hashmap-source-code.md
+++ b/docs/java/collection/hashmap-source-code.md
@@ -113,6 +113,24 @@ public class HashMap<K,V> extends AbstractMap<K,V> implements Map<K,V>, Cloneabl
 
   **threshold = capacity \* loadFactor**，**当 Size>threshold**的时候，那么就要考虑对数组的扩增了，也就是说，这个的意思就是 **衡量数组是否需要扩增的一个标准**。
 
+### <font color='red'>示例</font>
+
+`Map<Object, Object> map = new HashMap<>();`
+
+- 刚初始化情况下，`table`为空，`threshold = 0`,`size=0`(size 为实际存储数据大小)
+
+- 当调用`put`方法时，会调用 `resize()` 方法扩容，库容到 table 大小为 16 `threshold = (int)(*DEFAULT_LOAD_FACTOR* * *DEFAULT_INITIAL_CAPACITY*)` = 16 x 0.75 = 12
+
+- 是否要扩容判断
+
+  调用 `put`方法 -> `putVal` 添加完后会进行扩容校验
+
+  ```
+  ++modCount;
+  if (++size > threshold)
+  	resize();
+  ```
+
 **Node 节点类源码:**
 
 ```java