Java 对象多态equals toString 方法覆写

Myth丶恋晨 2023-01-06 14:55 196阅读 0赞

package com.msc.example;
    class TestA{ 
        private String name;
        private int age ;
        public TestA() { } ;
        public TestA(String name,int age){ 
            this.name = name ;
            this.age = age ;
        }
        @Override
        public boolean equals(Object obj){ 
            if(!(obj instanceof TestA)) return false ;
            if(obj == null) return false ;
            if(this == obj) return true ;
            TestA ta = (TestA) obj;
            return this.name.equals(ta.name) && this.age == ta.age ;
        }
        @Override
        public String toString() { 
            return "Test{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    '}';
        }
    }
    class TestB { 
        private String name;
        private int age;
        public TestB() {  }
        public TestB(String name, int age) { 
            this.name = name;
            this.age = age;
        }
    }
    public class JavaPoly { 
        public static void main(String[] args) { 
            TestA ta = new TestA("张三",20) ;
            TestA tab = new TestA("张三",20) ;
            TestA tac = new TestA("张三",21) ;
            TestB tb = new TestB("里斯",22);
            TestB tba = new TestB("里斯",22);
            System.out.println(ta);
            System.out.println(tb);
            System.out.println(ta.equals(tab));
            System.out.println(ta.equals(tac));
            System.out.println(tb.equals(tba));
            System.out.println("--------多态----------");
            Object obj = new int []{ 1,2,3} ; //向上转型
            if(obj instanceof int[]){ 
                int data[] = (int []) obj ;  //向下转型
                for(int temp : data){  System.out.println(temp+"、 ");
                }
            }
        }
    }

**输出**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]: /images/20221119/8f07e7c7d35e4dacbeb82211061cf041.png