Free practice · numeric · medium

Practice

Calculate an invoice subtotal

A function line_total(price, quantity, discount) returns price * quantity - discount. What does line_total(18, 3, 4) return?

Function contract trace

A caller supplies values and receives one defined result

  1. ContractDefine inputs, output, and failures
  2. ArgumentsEvaluate supplied values
  3. ParametersBind local names
  4. BodyRun focused local logic
  5. ReturnSend the result to the caller
  6. TestCheck the public contract

Keep argument evaluation, parameter binding, local state, return behavior, and external side effects visible at the function boundary.