Laravel relations doesn't return anything - php

Question

i have problem in laravel eloquent relationships.
there is 2 model in my application: article and category.
article model:
public function category()
{
return $this->belongsToMany('App\Category');
}
category model:
public function article()
{
return $this->hasMany('App\Article');
}
the relation between this tow is hasMany (Category -> article) & belongsToMany (Article -> category).
category will fetch by requested slug using this method at categoryController:
$category = Category::where('slug', '=', $slug)->get();
problem will be shown in view when i want to fetch articles from category and nothhing will return back:
#foreach ($category->article->all() as $article)
{{ $article->name }}
#endforeach
and from #dd($category->article) we will get empty collection:
Collection {#323 ▼
#items: []
}

Answer 1

As #lagbox tried to highlight in a comment, for pivot tables, both relationships should be belongsToMany. Inverse of hasMany is belongsTo.
If one article belongs to many categories, and one category can have many articles, then, ideally, there it should be a many-to-many relationship. Category model should have a belongsToMany relationship with Article model and vice versa. Additionally, there should be a pivot table, article_category. And as many have suggested, you can get articles the belongs to a category by using #foreach($category->articles as $articles)
You can read more about many to many here:
https://laravel.com/docs/5.8/eloquent-relationships#many-to-many

Answer 2

You can use #forelse blade directive like
#forelse ($category->article as $article)
<li>{{ $article->name }}</li>
#empty
<p>No articles</p>
#endforelse
You can check that here

Answer 3

You dont need to write $category->article->all() . $category->article itself will return all articles.
So just use like,
#foreach ($category->article->all() as $article)
{{ $article->name }}
#endforeach
For eager loading articles, you can use
with keyword
$category = Category::with('article')->where('slug', '=', $slug)->get();