Cannot pass the second requirement

Question about the task

Introducing generics

Java Collections, Level 5, Lesson 4

Resolved

Could anyone give some help how to satisfy the second requirement?

Parameterize the SomeClass and Solution classes as follows:
1. SomeClass must work with types that inherit Number;
2. Solution must work with types that inherit List, which in turn have SomeClass as a type argument.

Requirements:

The SomeClass class must work with types that inherit Number.
The Solution class must work with types that inherit List, which in turn have SomeClass as a type argument.
The Someclass class must be public.
The Someclass class must be static.
The SomeClass class must be in the Solution class..

package com.codegym.task.task35.task3502; import java.util.List; /* Introducing generics */ public class Solution <T extends List<? extends Number>> { public static class SomeClass<N extends Number> { } public static void main(String[] args) { } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

10 September 2020, 15:35

I think you may be overthinking this. A List that has a SomeClass type argument would simply be: List<SomeClass>

James Foo

Level 41 , Toronto, Canada

12 September 2020, 01:47

Isn't it using SomeClass in this way before its definition?

Guadalupe Gagnon

Level 37 , Tampa, United States

13 September 2020, 00:03

I am referring to line 8. Get rid of List<? extends Number> and put what i said above in.

James Foo

Level 41 , Toronto, Canada

14 September 2020, 02:16

here below is the error obtained following the suggestion, since adding SomeClass into line 8 is before its definition in line 9.

error: cannot find symbol
public class Solution<T extends List<SomeClass>> {
                                                           ^
  symbol: class SomeClass

public class Solution<T extends List<SomeClass>> {
    public static class SomeClass<N extends Number> {
    }

Guadalupe Gagnon

Level 37 , Tampa, United States

14 September 2020, 13:21

solution

You're right, my bad, it should be List<Solution.SomeClass> not List<SomeClass>

James Foo

Level 41 , Toronto, Canada

16 September 2020, 01:32

got you! Thanks for your help!