From 91fbabc2f906dc32034c1a53ee44399507b393a5 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Fri, 18 Sep 2026 11:16:00 +0800
Subject: [PATCH] =?UTF-8?q?day05--=E6=95=B0=E7=BB=84=E7=9A=84=E5=BC=82?=
 =?UTF-8?q?=E5=B8=B8=5F=E7=A9=BA=E6=8C=87=E9=92=88=E5=BC=82=E5=B8=B8?=
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---
 day05/src/com/inmind/array01/Demo04.java | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 day05/src/com/inmind/array01/Demo04.java

diff --git a/day05/src/com/inmind/array01/Demo04.java b/day05/src/com/inmind/array01/Demo04.java
new file mode 100644
index 0000000..ad186a7
--- /dev/null
+++ b/day05/src/com/inmind/array01/Demo04.java
@@ -0,0 +1,17 @@
+package com.inmind.array01;
+
+public class Demo04 {
+    public static void main(String[] args) {
+        int[] arr = {1, 2, 3};
+        //arr中保存的是堆内存的地址
+        System.out.println(arr[0]);//1
+        //null可以给引用数据类型进行初始化赋值
+        arr = null;
+        //如果引用数据类型，是null还继续操作，那就java.lang.NullPointerException（空指针异常）
+        //添加一些健壮性代码
+        if (arr != null) {
+            System.out.println(arr[0]);
+        }
+        System.out.println("程序正常结束");
+    }
+}