Welcome! This Scala lesson demystifies two key features: named arguments and default parameter values. They make function calls clearer and the code more maintainable.

Named arguments enhance code readability by associating each argument with a parameter name, thereby eliminating the need to remember their order. When using named arguments, you can place them in any order during the function invocation.

Imagine you're drawing a rectangle:

Named arguments make function invocations self-explanatory, reducing errors and improving readability.

Default parameter values automatically assign a predefined value to a function parameter. They permit the skipping of parameters that aren't required for the function call.

Consider a function that greets a user:

The first function call uses the default value, as no argument is passed.

The combination of both concepts brings flexibility and clarity.

Let's modify the drawRectangle function, adding a default color: