技術標籤：javajava

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("張三",20) ;
        TestA tab = new TestA("張三",20) ;
        TestA tac = new TestA("張三",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("--------多型----------");
        Object obj = new int []{1,2,3} ; //向上轉型
        if(obj instanceof int[]){
            int data[] = (int []) obj ;  //向下轉型
            for(int temp : data){ System.out.println(temp+"、 ");
            }
        }
    }
}

輸出