diff --git a/src/chapter5/Example24.java b/src/chapter5/Example24.java
new file mode 100644
index 0000000..7e34151
--- /dev/null
+++ b/src/chapter5/Example24.java
@@ -0,0 +1,4 @@
+package chapter5;
+
+public class Example24 {
+}
diff --git a/src/chapter5/Example25.java b/src/chapter5/Example25.java
new file mode 100644
index 0000000..bd7a99a
--- /dev/null
+++ b/src/chapter5/Example25.java
@@ -0,0 +1,4 @@
+package chapter5;
+
+public class Example25 {
+}
diff --git a/src/chapter5/demo55.java b/src/chapter5/demo55.java
new file mode 100644
index 0000000..812019b
--- /dev/null
+++ b/src/chapter5/demo55.java
@@ -0,0 +1,43 @@
+package chapter5;
+
+import java.time.LocalDate;
+import java.util.Scanner;
+
+public class demo55 {
+    public static void main(String[] args) {
+        Scanner scn = new Scanner(System.in);
+        System.out.println("请输入要判断的年份：");
+        int year = scn.nextInt();
+
+        System.out.println("方法一：" + year + "的2月有" + getNumOfDaysInFeb1(year) + "天");
+        System.out.println("方法二：" + year + "的2月有" + getNumOfDaysInFeb2(year) + "天");
+    }
+
+    /**
+     * 思路一
+     * @param year 年份
+     * @return 2月的天数
+     */
+    public static int getNumOfDaysInFeb1(int year) {
+        LocalDate date = LocalDate.of(year, 3, 1);
+        LocalDate feb = date.minusDays(1);
+        return feb.getDayOfMonth();
+    }
+
+    /**
+     * 思路二
+     * @param year 年份
+     * @return 2月的天数
+     */
+    public static int getNumOfDaysInFeb2(int year) {
+        LocalDate date = LocalDate.of(year, 1, 1);
+        if (date.isLeapYear()) {
+            return 29;
+        } else {
+            return 28;
+        }
+
+        // return date.isLeapYear() ? 29 : 28;
+    }
+
+}