Learning Functional Programming in Go

Before applying Replace Parameter with Method technique

We start with a getDiscountedPrice function that takes two parameter: lineItemPrice and discount:

 lineItemPrice := quantity * itemPrice; discount := getDiscount(); totalPrice := getDiscountedPrice(lineItemPrice, discount);

Replace Parameter with Method aggressively strives to reduce the number of parameters.

In this case we have two parameters. That is clearly fewer than the four parameters. Why reduce this low number of parameters?