Adrienne Tacke PRO
🇵🇭 Software Engineer & Sr. Developer 🥑 @ Cisco • Published Author • LinkedIn Learning Instructor • Twitch Streamer 🕹 Most important: I spend way too much money on desserts and endless hours playing Borderlands
Variables of the Veracious Variety:
How to better name your variables
@AdrienneTacke
👋 Copenhagen Developers Festival
"There are only two hard things in Computer Science: cache invalidation and naming things"
- Phil Karlton
naming things.
naming things
Why is naming important?
One
Why is it difficult?
Two
The 3 Cs of great variables
Three
Variable variables
Four
Why is naming important?
🌳
Naming is a way of placing order on our world by helping us differentiate between things.
Why is naming important?
🌳
Onyx
Tux
Domino
Oreo
Why is naming important?
🌳
Onyx
Why is naming important?
🌳
Adrienne
Why is naming important?
🌳
Adrienne
Why is naming important?
🌳
The way scientists name things
scientific nomenclature
Why is naming important?
🌳
Scientists prevent confusion by being specific.
specific
Why is naming important?
🌳
?
Why is naming important?
🌳
Say what strange White Oak is this...
It was a Rounded Oak, I believe.
The Rough Oak still stands, day after day!
Quercus alba
AKA "White Oak"
Why is naming important?
🌳
And there stood before me, a White Oak.
NOT White Oak
Possibly Maple
Why is naming important?
🌳
Carl Linnaeus
Swedish Naturalist
Why is naming important?
🌳
developed unique naming system
Every organism in the world is assigned a unique binomial name.
binomial name
Why is naming important?
🌳
binomial name
Homo
sapiens
genus
species modifier
Why is naming important?
🌳
binomial name
Homo
sapiens
genus
species modifier
Humans
Why is naming important?
🌳
Why is it difficult?
😑
Why is it difficult?
😑
Guidance on naming is mostly syntactical.
syntactical
Why is it difficult?
😑
syntactical
camelCase
kebab-case
PascalCase
snake_case
i
ht
long
TotalInventoryCountForEndOfDay
casing
length
auth
usr
Why is it difficult?
😑
syntactical
camelCase
kebab-case
PascalCase
snake_case
i
ht
long
TotalInventoryCountForEndOfDay
casing
length
auth
usr
"Use camelCase for variable names..."
"Avoid kebab-case since it clashes with subtraction syntax..."
"Use short identifier names for short scopes"
"Keep name length to a twenty five character maximum"
Why is it difficult?
😑
semantics
The meaning of names
Why is it difficult?
😑
semantics
The meaning of names
Why is it difficult?
😑
semantics
"Use meaningful, descriptive names..."
"Names should be nonambiguous."
"Try making identifiers self-documenting."
meaningful
descriptive
self-documenting
nonambiguous
Why is it difficult?
😑
semantics
meaningful
descriptive
self-documenting
nonambiguous
"meaningful"
"descriptive"
"self-documenting"
"nonambiguous"
Why is it difficult?
😑
meaningful
descriptive
self-documenting
nonambiguous
Names that are
are not enough...
Why is it difficult?
😑
correct
Names have to be
highly debatable
" "
.
Why is it difficult?
😑
homonyms
same words, different meaning
Why is it difficult?
😑
homonyms
homophones
homographs
"same writing"
same spelling, different meaning
"same sound"
same pronunciation, different meaning
Why is it difficult?
😑
homonyms
homophones
homographs
English
duck
"I took my pet duck to the Gucci store."
"Duck your head going while down the stairs!"
rock
"There was a great rock band last night."
"Almost four tons of solid rock had to be removed."
Why is it difficult?
😑
homonyms
homophones
homographs
English
duck
"I took my pet duck to the Gucci store."
"Duck your head going while down the stairs!"
rock
"There was a great rock band last night."
"Almost four tons of solid rock had to be removed."
write
"Turn right at the next intersection."
"Write a book, they said."
hour
"You are with me for the hour."
"What do you mean 'our' cake?"
right
our
English
Why is it difficult?
😑
homonyms
homophones
homographs
English
duck
"I took my pet duck to the Gucci store."
"Duck your head going while down the stairs!"
rock
"There was a great rock band last night."
"Almost four tons of solid rock had to be removed."
write
"Turn right at the next intersection."
"Write a book, they said."
hour
"You are with me for the hour."
"What do you mean 'our' cake?"
right
our
English
same spelling, different meaning
same pronunciation, different meaning
Why is it difficult?
😑
homonyms
skål
(cheers!)
Danish
skål
(bowl)
jul
(christmas)
hjul
(wheel)
tayo
(we)
Tagalog
tayo
(to stand)
basa
(to read)
basa
(wet)
Why is it difficult?
😑
synonyms
different words, same meaning
Why is it difficult?
😑
synonyms
Why is it difficult?
😑
synonyms
count
tally
enumeration of numbers
summation
keep count
to mark
Names
Concepts
Words chosen as identifiers
Associated meanings and perceptions tied to a name
Why is it difficult?
😑
Florian Deissenboeck · Markus Pizka
Concise and consistent naming
Published in Software Quality Journal (2006)
Why is it difficult?
😑
Source: Deissenboeck, F., & Pizka, M. (2006). Concise and consistent naming. Software Quality Journal, 14, 261-282.
Why is it difficult?
😑
Source: Deissenboeck, F., & Pizka, M. (2006). Concise and consistent naming. Software Quality Journal, 14, 261-282.
"In computer programs, homonyms pose an obstacle for program comprehension since the developer has to take all elements of the set Cn into account when spotting an identifier named n."
Why is it difficult?
😑
Source: Deissenboeck, F., & Pizka, M. (2006). Concise and consistent naming. Software Quality Journal, 14, 261-282.
"Synonyms unnecessarily increase the domain of N and the relation R...raising the learning effort of the language used."
Why is it difficult?
😑
Source: Deissenboeck, F., & Pizka, M. (2006). Concise and consistent naming. Software Quality Journal, 14, 261-282.
"On encountering name n1, which is synonym to n2, the reader must take concepts c1 and c2 into account."
Why is it difficult?
😑
Source: Deissenboeck, F., & Pizka, M. (2006). Concise and consistent naming. Software Quality Journal, 14, 261-282.
Ideally, we get to this
Why is it difficult?
😑
"When 334 developers were asked to choose 47 variable names, the median probability that two would choose the same name was just 6.9%."
Source: Feitelson, D. G., Mizrahi, A., Noy, N., Shabat, A. B., Eliyahu, O., & Sheffer, R. (2020). How developers choose names
How do we choose better variable names then?
The 3 Cs of Great Naming
🤩
The 3 Cs of Great Naming
🤩
Consistent
Concise
Correct
The 3 Cs of Great Naming
🤩
Concise
Correct
Consistent
Identifier needs to be unique enough to convey the concept.
The 3 Cs of Great Naming
🤩
Correct
Identifier needs to accurately convey the concept and minimize related concept space as much as possible.
Consistent
Concise
Identifier needs to be unique enough to convey the concept.
The 3 Cs of Great Naming
🤩
Consistent
Concise
Correct
Identifier needs to convey what is actually being assigned.
Identifier needs to accurately convey the concept and minimize related concept space as much as possible.
Identifier needs to be unique enough to convey the concept.
Variable Variables
🤓
Booleans
Can only be one of two values: true or false
Booleans
Can only be one of two values: true or false
isSomething
doesSomething
hasSomething
Examples:
isUpgrade, isApproval, isProMember
Examples:
allowsWhitespace, willUpdate, didRestart
Examples:
hasMoreThanOneWarning, hasMultipleDiscounts, hasException
condition: return True if at least one user is active
isUsersActive
const {something} = users.some(user => user.isActive);condition: return True if at least one user is active
isUsersActive
const isUsersActive = users.some(user => user.isActive);
isUsersActive
isUsersActive
condition: return True if at least one user is active
isAtLeastOneUserActive
isAtLeastOneUserActive
const isAtLeastOneUserActive = users.some(user => user.isActive);
isAtLeastOneUserActive
condition: return True if at least one user is active
isOneUserActive
isOneUserActive
const isOneUserActive = users.some(user => user.isActive);
isOneUserActive
condition: return True if at least one user is active
isSomeUserActive
isSomeUserActive
const isSomeUserActive = users.some(user => user.isActive);
isSomeUserActive
condition: return True if at least one user is active
isAnyUserActive
const isAnyUserActive = users.some(user => user.isActive);
🤩
Integers
Things understood to be numbers; counts/number of something
Integers
Things understood to be numbers; counts/number of something
{integer itself}
numberOfSomething
somethingCount
Examples:
age, year, MAXIMUM_ALLOWED_LOGIN_ATTEMPTS, tooltipDelayInMilliseconds
Examples:
numberOfRetries, numberOfDescendants, numberOfAccounts, numberOfDaysWithoutRain
Examples:
failureCount, retryCount, currentCakeInventoryCount
condition: return number of eligible discount items that are part of a customer's order.
numberOfEligibleItemsWithinTransaction
condition: return number of eligible discount items that are part of a customer's order.
numberOfEligibleItemsWithinTransaction
numberOfEligibleItemsInTransaction
condition: return number of eligible discount items that are part of a customer's order.
numberOfEligibleItemsWithinTransaction
numberOfEligibleItemsInTransaction
numberOfEligibleItems
condition: return number of eligible discount items that are part of a customer's order.
numberOfEligibleItemsWithinTransaction
numberOfEligibleItemsInTransaction
numberOfEligibleItems
numberOfEligibleDiscountItems
🤩
Floating-Point Numbers
Unrounded measures;
numbers that are not integers
Floating-Point Numbers
Unrounded measures; numbers that are not integers
{floating-point itself}
somethingAmount
Examples:
height, weight, priceInDanishKrone, angleInDegrees, highTemperatureInFahrenheit
Examples:
discountAmount, transferAmount, refundAmount
Strings
Labels; typically a sequence of characters
Strings
Labels; typically a sequence of characters
{entity itself}
somethingAsString
Examples:
fullGivenName, city, shortSpeakerBiography, playerSelectedClass, definition
Examples:
monthAsString, timeZoneAsString
Collections
Arrays, lists, or sets; groups of things
Collections
Arrays, lists, or sets; groups of things
{plural form of thing}
implementationOfThings
Examples:
robots, sentientRobots, discountedProducts, customers, newlyReleasedBooks
Examples:
unorderedListOfCustomers, queueOfFirstPriorityTasks, orderedSetOfTimeStamps
Maps
Accessing values by keys
Maps
Accessing values by keys
keyToValueMap
Examples:
bookIdToAuthorMap, customerToOrderTotalMap, productIdToSuppliersMap
Pairs & Tuples
Typically stored together; items of the same type
Pairs & Tuples
Typically stored together and items of the same type
firstPairAndSecondPair
Examples:
lengthAndWidth, setsAndRepitions, currentAndLifetimeXP, genusAndSpecies
firstSecondAndThirdThing
Examples:
heightWidthAndDepthInCentimeters, saturatedTransAndTotalFatInGrams, redGreenBlueAndAlpha
"Great code is understood; rarely is it interpreted."
- Adrienne Braganza Tacke
Salamat/Tak #CPHDevFest!
Adrienne Braganza Tacke
@AdrienneTacke
Currently writing this!
🤔🍰 Know a good pâtisserie/bakery?
Please come find me and let's chat!
Variables of the Veracious Variety
By Adrienne Tacke
Variables of the Veracious Variety
First presented at Copenhagen Developers Festival (August 2023) As the famous Phil Karlton quote goes: "There are only two hard things in Computer Science: cache invalidation and naming things". This talk focuses on one of those things: naming! Why is naming so difficult? How do we craft concise, clear, and consistent variable names? What makes a variable name concise, clear, and consistent? In this talk, I'd like to discuss the importance of naming, walk through examples of variable names and improve them, and set some clear guidelines and tips on how to name things. By the end of this talk, you'll leave with the indispensable skill of effectively naming things!
