Introduce Parameter Object

Goal

Related arguments travel together as one well-named value object that the function (and callers) refer to by name.

Before the refactoring

function record(low, high, value) {
  // ...
}

After the refactoring

class NumberRange { /* low, high */ }
function record(range, value) {
  // ...
}

Savings

Adding a related field is one type change instead of touching every call site; intent is named.

Note

Premature parameter objects hide which fields are actually needed by which method — wait until the clump appears in 3+ places before extracting.