Untitled Presentation

How to Name Things

Two Hard Problems in Computer Science

Phil Karlton

IT World

Coding Horrors

if (data) {
	if (data.data) {
		data = data.data;
	}
}

addBottomWhiteBorderIfFirstOfMultipleCarousel();
					

Programming is communication

Lesser mortals write for computers

Great developers write for humans

Experiment

Give a name for the variable

decimal ??? = 0;

forEach (item in cart)
{
	??? += item.Price;
}
					

Conversation

Leverage mutual knowledge

Engage in reflexive thinking

Good names are

Bad names are

Things

Concept

Library | Namespace

Class | Module

Function | Method | Procedure | Routine

Variable

Casing Conventions

PascalCase

camelCase (lower)

snake_case

SCREAMING_SNAKE_CASE

train-case

Naming Conventions

• C# Pascal for classes, methods; Camel for variables
• Java Pascal for classes; Camel for methods, variables
• Python Pascal for classes; Camel/Snake for functions, variables
• Ruby Camel for classes; Snake for functions, variables
• JavaScript Camel for constructors; Camel for functions, variables

Stick to the convention of a language, even in mixed-language programming Exception: if developers cross languages frequently

Variable Naming

Ideas

• Prefer why > what THREE = 3 (bad)
• Look to domain terminology
• Identify points of variation
• Use opposites previous/next
• Use literal phrases totalCustomersInCanada
• Contextualize with qualifiers itemPrice vs item.price

Variable Naming

Guidelines

• Use ASCII characters only
• Avoid confusing characters oO0iIl1
• Avoid words with multiple meanings number
• Avoid overloading established words stack
• Use full words and standard abbreviations

Variable Naming

Guidelines

• Standardize order of qualifiers fruitTotal vs totalFruit
• Spellcheck US or UK
• Prefix booleans with is- or has-
• Avoid negatives isInactiveDisabled
• Pluralize enums and collections

Variable Naming

Exercise

Replace condition with variable

string displayName;

if (patient != null
    && patient.name != null
    && patient.name != ""
    && !privacyPolicy.isAnonymous(patient))
{
	displayName = String.format("Patient {0}", patient.name);
}
else
{
	displayName = "X";
}
					

Function Naming

Ideas

• Prefer why > how
• Look to domain terminology
• Refer to recognized patterns Factory.create()
• Look for established concepts push, pop, flush
• Think symmetry open(file)/close(file)

Function Naming

Guidelines

• Use prepositions for transformations celsiusToFarenheit()
• Standardize syntax of getters/setters Product.Price() vs Product.GetPrice()
• Avoid words with multiple meanings number
• Avoid overloading established words stack
• Use full words and standard abbreviations

Function Naming

Exercise

Name the function

public TaxRules ??? (PricingContext context)
if (context.hasTaxOverride) {
	return context.getTaxOverride();
}
else if (context.isTaxFree) {
	return new NullTaxRules();
}
else if (context.geo !== null) {
	if (!context.geo.isInEu) {
		return new EuTaxRules();
	}
	else {
		return new DefaultTaxRules();
	}
}
else {
	return null;
}
					

Concept Naming

Ideas

• Create portmanteaus facetime
• Use metaphors and analogies token
• Invoke imagery toast
• Tell a story bug
• Consult a thesaurus

Concept Naming

Guidelines

• Avoid made-up words cystilizer
• Avoid overloaded words kernel
• Avoid trademarks Xerox, Google

Concept Naming

Exercise

Pull to refresh components

Fast Company

Fluffy Words Greylist

• Verbs do, handle, process, perform
• Nouns callback, car1 car2, data, feature, handler, manager, object, thing
• Adjectives fast, normal, smart, temp

THE END

Credits

Background Images (in order of appearance)

• Daniel Lombraña González, "La piedra Rosetta", https://www.flickr.com/photos/teleyinex/4983505622, CC Attribution-ShareAlike 2.0, with modifications to darken image;
• Board of European Students of Technology, "Discussion group during GA", https://www.flickr.com/photos/bestorg/8733059592/, CC Attribution-NonCommercial 2.0, with modifications to darken image;
• Pixabay, https://pixabay.com/en/word-cloud-words-tag-cloud-679936/, CC0 Public Domain, with darkened and lightened variants;