public function getTotalTax()
    {
        $amount = 0;

        if ($this->Price && $this->TaxRate && $this->Quantity) {
            $amount = ((($this->Price * $this->Quantity) - $this->Discount) / 100) * $this->TaxRate;
        }
        
        return $amount;
    }
public function getTotalTax()
    {
        $amount = 0;

        if ($this->Price && $this->TaxRate && $this->Quantity) {
            $amount = ((($this->Price * $this->Quantity) - $this->Discount) / 100) * $this->TaxRate;
        }
        
        return $amount;
    }
public function getTotalTax ( ) { $ amount = 0 ; if ( $ this -> Price && $ this -> TaxRate && $ this -> Quantity ) { $ amount = ( ( ( $ this -> Price * $ this -> Quantity ) - $ this -> Discount ) / 100 ) * $ this -> TaxRate ; } return $ amount ; }
Find the tax cost for all of the items in this line.

@return Currency
Find the tax cost for all of the items in this line .