Laravel :: Type error: Too few arguments to function AppProduct::getTax(), 0 passed - development

Laravel :: Type error: Too few arguments to function AppProduct::getTax(), 0 passed

I have this code:

public function taxesData(Product $product)
{
    $taxes = Auth::user()->taxes;
    foreach ($taxes as $tax) {
        echo "$product->getTax($tax)";
    }
}

which on testing gives this error:

Type error: Too few arguments to function AppProduct::getTax(), 0 passed in E:projectsimsvendorlaravelframeworksrcIlluminateDatabaseEloquentConcernsHasAttributes.php on line 411 and exactly 1 expected

However, just a small change makes it works, but I am not able to understand. Why?

public function taxesData(Product $product)
{
    $taxes = Auth::user()->taxes;
    foreach ($taxes as $tax) {
        echo $product->getTax($tax);
    }
}

Please help.

I tried to simplify it for the purpose of posting here… actually i am creating json with html component for a datatable ->

public function taxesData(Product $product)
{
    $taxes = Auth::user()->taxes;
            return datatables()
        ->of($taxes)
        ->addColumn('check',function($tax) use($product){
            if($product->hasTax($tax)){
                return "<input type='checkbox' class='input-sm row-checkbox' name='tax[$tax->id]' value='$tax->id' checked>";
            }else{
                return "<input type='checkbox' class='input-sm row-checkbox' name='tax[$tax->id]' value='$tax->id'>";
            }
        })
        ->editColumn('tax', function($tax) use($product){
            return "<span class='currencyinput form-control'>
                    <input id='rate' type='text' name='rate' value='$product->getTax($tax)' required autofocus>
                    </span>"
        })
        ->toJson();
}

from Laravel Questions and Answers https://laravelquestions.com/php/laravel-type-error-too-few-arguments-to-function-appproductgettax-0-passed/
via Lzo Media