diff --git a/src/chapter3/Example01.java b/src/chapter3/Example01.java
index 4e52636..8111bf1 100644
--- a/src/chapter3/Example01.java
+++ b/src/chapter3/Example01.java
@@ -1,37 +1,37 @@
 package chapter3;
 
-class Student {
-    String name;
-    int age;
-    String sex;
-
-    void read() {
-        System.out.println("大家好，我是" + name + "，我在看书！");
-    }
-
-    void introduce() {
-        System.out.println("大家好，我叫" + name + "，我今年" + age + "岁了，我是" + sex + "孩");
-    }
-}
-
-public class Example01 {
-    public static void main(String[] args) {
-        Student s1 = new Student();
-        Student s2 = new Student();
-
-        s1.name = "小明";
-        s1.sex = "男";
-        s1.age = 20;
-
-
-        s2.name = "小红";
-        s2.sex = "女";
-        s2.age = 19;
-
-        s1.read();
-        s2.read();
-
-        s1.introduce();
-        s2.introduce();
-    }
-}
+//class Student {
+//    String name;
+//    int age;
+//    String sex;
+//
+//    void read() {
+//        System.out.println("大家好，我是" + name + "，我在看书！");
+//    }
+//
+//    void introduce() {
+//        System.out.println("大家好，我叫" + name + "，我今年" + age + "岁了，我是" + sex + "孩");
+//    }
+//}
+//
+//public class Example01 {
+//    public static void main(String[] args) {
+//        Student s1 = new Student();
+//        Student s2 = new Student();
+//
+//        s1.name = "小明";
+//        s1.sex = "男";
+//        s1.age = 20;
+//
+//
+//        s2.name = "小红";
+//        s2.sex = "女";
+//        s2.age = 19;
+//
+//        s1.read();
+//        s2.read();
+//
+//        s1.introduce();
+//        s2.introduce();
+//    }
+//}
diff --git a/src/chapter3/Example05.java b/src/chapter3/Example05.java
index 2ca9e79..4d582aa 100644
--- a/src/chapter3/Example05.java
+++ b/src/chapter3/Example05.java
@@ -8,6 +8,10 @@ class Book {
 //        this.id = 0;
 //        this.name = "未命名";
 //        System.out.println("初始化：无参构造被调用！");
+//    }
+
+//    public Book(int id, String name) {
+//        this.id = id;
 //    }
 
     // 打印信息
diff --git a/src/chapter3/Example09.java b/src/chapter3/Example09.java
new file mode 100644
index 0000000..7ef2a86
--- /dev/null
+++ b/src/chapter3/Example09.java
@@ -0,0 +1,22 @@
+package chapter3;
+
+class Student {
+    private String name;
+    private int age;
+
+    public Student(String name, int age) {
+        name = name;
+        age = age;
+    }
+
+    public void read() {
+        System.out.println("我是" + name + "，我今年" + age + "岁");
+    }
+}
+
+public class Example09 {
+    public static void main(String[] args) {
+        Student stu = new Student("小明", 15);
+        stu.read();
+    }
+}