From 8695169cfb6b6ff3068d21727ae906bc0cd520ec Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Tue, 23 Dec 2025 15:03:17 +0800
Subject: [PATCH] =?UTF-8?q?java=E4=B8=AD=E7=9A=84=E6=95=B0=E6=8D=AE?=
 =?UTF-8?q?=E7=B1=BB=E5=9E=8B=E5=92=8C=E5=8F=98=E9=87=8F=E5=AE=9A=E4=B9=89?=
 =?UTF-8?q?=E7=BB=83=E4=B9=A0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 day01/src/com/inmind/Demo02.java | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/day01/src/com/inmind/Demo02.java b/day01/src/com/inmind/Demo02.java
index eafa49c..2cd4fbb 100644
--- a/day01/src/com/inmind/Demo02.java
+++ b/day01/src/com/inmind/Demo02.java
@@ -21,29 +21,37 @@ Java中的默认类型：整数类型是int 、浮点类型是double 。
  */
 public class Demo02 {
     public static void main(String[] args){
-        //定义字节型变量
-        byte b = 100;
+        //定义字节型变量（1个字节）
+        byte b = -128;
+        b = 100;
         System.out.println(b);
-        //定义短整型变量
-        short s = 1000;
+        //定义短整型变量（2个字节）
+        short s = -32768;
         System.out.println(s);
         //定义整型变量
         int i = 123456;
         System.out.println(i);
-        //定义长整型变量
+        //定义长整型变量(8字节)
         long l = 12345678900L;
         System.out.println(l);
         //定义单精度浮点型变量
         float f = 5.5F;
         System.out.println(f);
         //定义双精度浮点型变量
-        double d = 8.5;
+        double d = -8.5;
         System.out.println(d);
         //定义布尔型变量
+        //ctrl+D:复制一行
         boolean bool = false;
+        boolean bool1 = true;
         System.out.println(bool);
         //定义字符型变量
-        char c = 'A';
+        char c = ' ';
         System.out.println(c);
+        //注意事项：变量可以先定义后赋值的，但是使用之前必须赋值
+        //定义一个num的int型变量，不赋值
+        int num;
+        num = 200;
+        System.out.println(num);
     }
 }