Review this class. Are the names meaningful and consistent?

← Getting Started · Ref: Q1026

The first draft of this class had two naming issues, both fixed in the code shown here:

1. The discount method was called 'proc' - too abbreviated. It is now 'applyDiscount'. Method names should describe the action clearly.

2. The local for the discount amount was called 'x' - meaningless. It is now 'discountAmount' (and 'saving' in the program). Local variables should describe what the value represents.

The rest of the naming was already fine and is unchanged:
- 'Order' is a clear class name
- 'totalPrice' and 'customerName' are descriptive fields
- 'applyDiscount' clearly states the action
- 'discountRate' describes the parameter's role

Good naming makes code self-documenting. A reader should understand the purpose of each variable without reading the implementation.

Example

defines module qa.gettingstarted.reviewernaming

  defines class

    Order
      totalPrice as Float?
      customerName as String?

      default private Order()

      Order()
        ->
          name as String
          price as Float
        this.customerName: name
        this.totalPrice: price

      applyDiscount()
        -> discountRate as Float
        <- discountAmount as Float: Float()

        if discountRate?
          discountAmount: totalPrice * discountRate

      override operator ? as pure
        <- rtn as Boolean: customerName? and totalPrice?

      operator $ as pure
        <- rtn as String: `Order for ${customerName}`

  defines program

    NamingReviewDemo()
      stdout <- Stdout()

      order <- Order("Alice", 100.0)
      saving <- order.applyDiscount(0.15)
      stdout.println(`${order} saving: ${saving}`)

Common mistakes

E11031 — The name 'val' is one of the banned non-descriptive variable names, so 'val <- ...' triggers E11031 — use a descriptive name like saving. See ek9 -h E11031 for details.

Incorrect:

      val <- order.applyDiscount(0.15)
      stdout.println(`${order} saving: ${val}`)

Correct:

      saving <- order.applyDiscount(0.15)
      stdout.println(`${order} saving: ${saving}`)

Coming from another language?

EK9 naming follows the same clean-code principles as any language. Use descriptive names that state purpose.

Keywords: review, quality, readable, clean, naming