1.二维数组
2.单个对象实现链表
public class User {
private String userName;
static User user;
private User next;
public User(String userName){
this.userName=userName;
next = user;
user=this;
}
public static void main(String args[]){
User u1 = new User("a");
User u2 = new User("b");
User u3 = new User("c");
do{
System.out.println(User.user);
}while((user=user.next) !=null);
}
public String toString(){
return this.userName;
}
}
//二维数组
int[][] a={{1,1,1},{2,2},{3,3}};
int sum=0;
System.out.println(a.length); //a的长度
for(int i=0;i<a.length;i++){
for(int j=0;j<a[i].length;j++){ //二给数组里面的一维数组的长度
System.out.println("i="+i+" , j="+j);
sum+=a[i][j];
}
}
System.out.println(sum);