Terminology: Arguments vs Parameters

We should mention that we are slightly simplifying terminology here. We conflate two terms that normally would be defined separately: We simply use the term “argument” for both the variable names that are defined in the arguments list of the method definition, and the value that is passed as part of the method call.

In programming, normally the “argument list” is called a “parameter list” instead, and a single name on it is called a “parameter”. On the other hand, only the objects passed when calling the method are referred to as “arguments”.

E.g. in the code …

def add_two(number)
  number + 2

puts add_two(3)

… the word number in the first line is a “parameter”, whereas 3 in the last line is an “argument”.

We found making this distinction in our beginners classes unnecessarily confusing, and thus ignore it. We simply call both these things “arguments”, and point out that they create a local variable inside of the method body.

So, now you know :)