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.
InvoiceLineTotal(items: list<LineItem>) → int
C# needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
public int InvoiceLineTotal(List<LineItem> items) {
}Worked examples
| Call | Result |
|---|---|
InvoiceLineTotal(new List<LineItem> { new LineItem("Widget", 3, 500) }) | 1500 |
InvoiceLineTotal(new List<LineItem> { new LineItem("A", 2, 1000), new LineItem("B", 1, 300) }) | 2300 |
InvoiceLineTotal(new List<LineItem> { }) | 0 |
InvoiceLineTotal(new List<LineItem> { new LineItem("X", 0, 999) }) | 0 |
Hint
Walk the list, multiply each line, and add.
Reference solution in C#
public int InvoiceLineTotal(List<LineItem> items) {
int total = 0;
foreach (var item in items) total += item.Qty * item.UnitPrice;
return total;
}