How to call method inside laravel View?

I have controller which will load the view part

public function homePage(){
    $categories = Category::all();
    $products = Product::all();
    return view('cart.index',compact('categories','products'));
}

Here is the View (basically checking for subcategory if there it will show otherwise skip)

<ul class="list-group list-group-bordered list-group-noicon uppercase">
    <li class="list-group-item active">
        @foreach($categories as $row)
            <a class="dropdown-toggle" href="#"></a>
            @if()
                @foreach($subcategories as $sub)
                    <ul>                                        
                        <li><a href="#"><span class="size-11 text-muted pull-right">(123)</span> </a></li>          
                    </ul>
                @endforeach 
            @else
                <li class="list-group-item"><a href="#"><span class="size-11 text-muted pull-right">(189)</span> </a></li>
            @endif
        @endforeach

    </li>
</ul>   

Here is the checkSubcategory method

public function checkSubcategory($id){
    $category = Category::find($id);
    $id = $category->id;
    $subcategories = DB::table ('subcategories')
        ->join('categories_subcategories','subcategories.id','=','categories_subcategories.subcategory_id')
        ->join('categories','categories_subcategories.category_id','=','categories.id')
        ->where('categories.id','=',$id)
        ->select('subcategories.name as s_name ')
        ->get(); 

    return $subcategories;
}

But i got syntax Error in line of calling method in View? what could be the error ..is there any mistake calling method in view part?

via User57