From 54ea3ca515b0082a4daa59dd5f15537f8ed268bb Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sat, 21 Mar 2026 10:55:10 +0800
Subject: [PATCH] =?UTF-8?q?=E8=BF=9B=E9=98=B6day09-=E5=AD=97=E8=8A=82?=
 =?UTF-8?q?=E6=95=B0=E7=BB=84=E5=92=8C=E5=AD=97=E7=AC=A6=E4=B8=B2=E7=9A=84?=
 =?UTF-8?q?=E7=9B=B8=E4=BA=92=E8=BD=AC=E6=8D=A2?=
MIME-Version: 1.0
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---
 javaSE-day09/src/com/inmind/io01/Demo4.java | 40 +++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 javaSE-day09/src/com/inmind/io01/Demo4.java

diff --git a/javaSE-day09/src/com/inmind/io01/Demo4.java b/javaSE-day09/src/com/inmind/io01/Demo4.java
new file mode 100644
index 0000000..041f387
--- /dev/null
+++ b/javaSE-day09/src/com/inmind/io01/Demo4.java
@@ -0,0 +1,40 @@
+package com.inmind.io01;
+
+import java.util.Arrays;
+
+/*
+字节数组和字符串的相互转换
+
+	字节数组--->字符串:构造方法
+    	String(byte[] bytes) 通过使用平台的默认字符集解码指定的字节数组来构造新的 String 。
+    	String(byte[] bytes, int offset, int length) 通过使用平台的默认字符集解码指定的字节子阵列来构造新的 String
+    字符串--->字节数组:成员方法
+        byte[] getBytes() 使用平台的默认字符集将该 String编码为一系列字节，将结果存储到新的字节数组中。
+
+    注意:
+        1.UTF-8:字母和数字都只占1个字节,而一个中文占3个字节
+        2.GBK:字母和数字都只占1个字节,而一个中文占2个字节
+ */
+public class Demo4 {
+    public static void main(String[] args) {
+        String str = "abc";
+        //字符串--->字节数组
+        byte[] bytes = str.getBytes();
+        System.out.println(bytes.length);
+        System.out.println(Arrays.toString(bytes));
+
+        String str1 = "中国";
+        byte[] bytes1 = str1.getBytes();
+        System.out.println(bytes1.length);
+        System.out.println(Arrays.toString(bytes1));
+
+        //字节数组--->字符串
+        String s1 = new String(bytes);
+        System.out.println(s1);
+        String s2 = new String(bytes1);
+        System.out.println(s2);
+
+        String s3 = new String(bytes1, 3, 3);
+        System.out.println(s3);
+    }
+}