From 61d11ecc4d889d775ede31bb1803bca4560f3532 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Mon, 27 Jul 2026 16:17:06 +0800
Subject: [PATCH] =?UTF-8?q?day10-=E7=94=A8instanceof=E5=85=B3=E9=94=AE?=
 =?UTF-8?q?=E5=AD=97=E8=BF=9B=E8=A1=8C=E7=B1=BB=E5=9E=8B=E5=88=A4=E6=96=AD?=
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---
 .../src/com/inmind/object_cast10/Demo11.java  | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 day10/src/com/inmind/object_cast10/Demo11.java

diff --git a/day10/src/com/inmind/object_cast10/Demo11.java b/day10/src/com/inmind/object_cast10/Demo11.java
new file mode 100644
index 0000000..cef3223
--- /dev/null
+++ b/day10/src/com/inmind/object_cast10/Demo11.java
@@ -0,0 +1,44 @@
+package com.inmind.object_cast10;
+/*
+如何在代码中判断出当前的多态父类类型是不是对应的子类类型呢？
+instanceof 关键字
+    多态类型 instanceof 子类类型 会有一个返回值 boolean
+    true: 多态类型就是子类类型，（animal是一个猫）
+    false:多态类型就不是子类类型，（animal不是一个猫）
+ */
+public class Demo11 {
+    public static void main(String[] args) {
+        //来一只猫和狗
+        Cat cat = new Cat();
+        Dog dog = new Dog();
+        eat(cat);
+        eat(dog);
+    }
+    //推导多态的好处:以不变应万变
+    public static void eat(Animal animal) {//Animal a = cat|dog; 多态
+        System.out.println("动物开始吃：");
+        animal.eat();
+        //动物吃完之后，想让它干点活，如果是狗看门，如果是猫抓老鼠
+        if (animal instanceof Dog) {//转换成指定子类对象，调用独有功能
+            Dog dog = (Dog) animal;
+            dog.lookHome();
+        }
+        if (animal instanceof Cat) {//使用instanceof，避免了向下转型的风险！！
+            Cat cat = (Cat) animal;
+            cat.catchMouse();
+        }
+    }
+
+
+    /*//定义一个猫吃东西的方法
+    public static void eat(Cat cat) {//Cat cat = cat;
+        System.out.println("动物开始吃：");
+        cat.eat();
+    }
+    //定义一个狗吃东西的方法
+    public static void eat(Dog dog) {//Dog dog = dog;
+        System.out.println("动物开始吃：");
+        dog.eat();
+    }*/
+
+}