问题

public class Human {
static String home = "地球" ;
String name = "人" ;

public static class Brain { // nested class (嵌套类)
    
    String name = "脑子" ;
    
    public void show() {
        System.out.println("Human home : " + Human.home  );
        System.out.println("Brain name : " + this.name  );
    }
    
}

public class Heart { // non-static member class (实例内部类)
    
    String name = "心脏" ;
    
    public void show() {
        System.out.println("Human home : " + Human.home  );
        System.out.println("Human name : " + Human.this.name  );
        System.out.println("Brain name : " + this.name  );
    }
    
}

1.System.out.println("Human home : " + Human.home ); 调用宿主类的变量要用宿主类的 类名.字段名 来调用

2.ZoneId zoneId = ZoneId.of( "Europe/London" );

System.out.println( zoneId );

TimeZone zone = TimeZone.getTimeZone( "Asia/Shanghai" );

System.out.println( zone );

这两者的区别是什么？

吐槽