java入门第二季--继承--Object类_java教程

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java入门第二季--继承--Object类

发布时间：2019-11-17 发布网站：脚本宝典

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Object类
 
 toString()方法
 
 
 代码
 /javaDemo3/src/com/imooc/Animal.java
                             
       
package com.imooc;  public class Animal {     public Animal() {      } } 
 /javaDemo3/src/com/imooc/Dog.java
                             
       
package com.imooc; import java.util.*; public class Dog extends Animal {      public Dog() {         System.out.PRintln("Dog类执行了" );     }  } 
 /javaDemo3/src/com/imooc/InITail.java
                             
       
package com.imooc;  public class Initail {      public static void main(String[] args) {         @H_810_126@// TODO Auto-generated method stub         Dog dog = new Dog();         System.out.println(dog);     }  } 
 
 重写toString()方法
 /javaDemo3/src/com/imooc/Dog.java
右键 -> source -> genenor toString
]
                             
       
package com.imooc; import java.util.*; public class Dog extends Animal {      public Dog() {         System.out.println("Dog类执行了" );     }      public String toString() {         return "Dog [age=" + age + "]";     }  } 
 
 equals
 /javaDemo3/src/com/imooc/Initail.java
                             
       
package com.imooc;  public class Initail {      public static void main(String[] args) {         Dog dog = new Dog();         Dog dog2 = new Dog();         if(dog.equals(dog2)) {             System.out.println("两个对象是相等的");         }else {             System.out.println("两个对象是不相等的");         }     }  } 
 
 重写equals
右键-> source-> generate->hascode equals
 /javaDemo3/src/com/imooc/Dog.java
                             
       
package com.imooc; import java.util.*; public class Dog extends Animal {     public int age = 20;     public void eat() {         System.out.println("年龄:"+age+ "狗可以吃东西" );     }     public Dog() {         System.out.println("Dog类执行了" );     }     public void method() {         System.out.println(age);         System.out.println("suPEr" + super.age);         eat();         super.eat();     }     public String toString() {         return "Dog [age=" + age + "]";     }      public boolean equals(Object obj) {         if (this == obj)             return true;         if (obj == null)             return false;         if (getClass() != obj.getClass())             return false;         Dog other = (Dog) obj;         if (age != other.age)             return false;         return true;     }  } 
 /javaDemo3/src/com/imooc/Initail.java
                             
       
package com.imooc;  public class Initail {      public static void main(String[] args) {          Dog dog = new Dog();         Dog dog2 = new Dog();           if(dog.equals(dog2)) {             System.out.println("两个对象是相等的");         }else {             System.out.println("两个对象是不相等的");         }     }  }