Name Your Functions

Contributed by: Maximiliano Contieri

Difficulty level: Easy

Clear and concise function names are crucial for communication between developers and the codebase. Poorly named functions can lead to confusion, misinterpretation, and potential bugs. Let’s discuss how you should name your abstractions.

Imagine a scenario where you encounter a function named doSomething(). Can you confidently deduce its purpose or predict its behavior? Probably not. Choosing good names is not a difficult task when you learn the rules and the behavior or the real-world domain you want to simulate.

Examine this JavaScript example and try to understand what it does:

function calculateTotalCost(items, rate) {
  var total = 0;
  for (const item of items) {
    total += item.getPrice();
  }
  return total * (1 - rate);
}

The name calculateTotalCost describes what the function does but is not intention-revealing. If you step back from the implementation and understand what the function’s purpose is you will realize it is applying a discount rate. A better or more semantic name would be:

function applyDiscount(items, discountRate) {
  var total = 0;
  for (const item of items) {
    total += item.price();
  }
  return total * (1 - discountRate);
}

The best names are always in the real world and seldom in the computation domain.

Look back at the original example and notice the getPrice() function. This is too imperative and implementational because it belongs to the computation domain of technical jargon rather ...