集合中存储的实际上是对象的引用
import java. util.ArrayList ;
import java. util.List ;
class Apple{
private String color ;
private String type ;
public Apple (String color, String type) {
super();
this.color = color;
this.type = type;
}
}
public class Main {
public static void main (String[] args) {
Apple apple1 = new Apple("red" ,"type1");
Apple apple2 = new Apple("green" ,"type2");
List <Apple> apples = new ArrayList<Apple>(4 );
apples .add( apple1);
apples .add( apple2);
}
}
