Sum the invoice line items
An invoice lists items with quantity and unit price. Compute the total across all lines.
- Each line contributes qty multiplied by unitPrice.
- An empty list totals zero.
invoice_line_total(items: list<LineItem>) → int
Where you start
def invoice_line_total(items: list[LineItem]) -> int:
Worked examples
| Call | Result |
|---|---|
invoice_line_total([LineItem(name="Widget", qty=3, unit_price=500)]) | 1500 |
invoice_line_total([LineItem(name="A", qty=2, unit_price=1000), LineItem(name="B", qty=1, unit_price=300)]) | 2300 |
invoice_line_total([]) | 0 |
invoice_line_total([LineItem(name="X", qty=0, unit_price=999)]) | 0 |
Hint
Walk the list, multiply each line, and add.
Reference solution in Python
def invoice_line_total(items: list[LineItem]) -> int:
return sum(item.qty * item.unit_price for item in items)