How would you define high quality code?

What would be the main attributes of good code?

Comments

[Fabian Schultz]

There's a really great chapter about this in "Game Programming Patterns" by Robert Nystrom:

For me, good design means that when I make a change, it’s as if the entire program was crafted in anticipation of it. I can solve a task with just a few choice function calls that slot in perfectly, leaving not the slightest ripple on the placid surface of the code.

That sounds pretty, but it’s not exactly actionable. “Just write your code so that changes don’t disturb its placid surface.” Right.

Let me break that down a bit. The first key piece is that architecture is about change. Someone has to be modifying the codebase. If no one is touching the code — whether because it’s perfect and complete or so wretched no one will sully their text editor with it — its design is irrelevant. The measure of a design is how easily it accommodates changes. With no changes, it’s a runner who never leaves the starting line.

Be sure to read the whole thing!

[Ben Halpern]

I like this a lot. "Accommodation to changes" accounts for readability, organization, testing, and a lot of other things bundled in.

Coding only for the problem at hand right now: Bad.
Coding for every possible future need: Bad.
Coding to solve current problems while being accommodating towards future modifications: Good.

[Julia Torrejón]

Coding for every possible future need: Bad.

I have seen this scenario a few times and it obviously delays the whole project because requirements keep changing and so does the code.

[Max Cerrina]

This. There are few things that I feel like are as satisfying as being like "Oh crap, I need to make sure it can handle ABC" or "I need to change it for this new thing" and realizing you wrote it such that sure, it does need to change somewhere, but it has that capability for change without things getting messy. The opposite of having to add more and more logic to handle cases.

[Julia Torrejón]

A few points taken from Robert Nystrom are:

• Key goal of software architecture: minimize the amount of knowledge you need to have in-cranium before you can make progress.
• Get problem -> Learn Code -> Code Solution -> Clean up
• Change to one piece of code doesn’t necessitate a change to another. We obviously need to change something, but the less coupling we have, the less that change ripples throughout the rest of the game.
• Good architecture makes a huge difference in productivity. It’s hard to overstate how profound an effect it can have.
• Good architecture takes real effort and discipline. Every time you make a change or implement a feature, you have to work hard to integrate it gracefully into the rest of the program. You have to take great care to both organize the code well and keep it organized throughout the thousands of little changes that make up a development cycle.
• You have to think about which parts of the program should be decoupled and introduce abstractions at those points. 
• Writing well-architected code takes careful thought, and that translates to time. Maintaining a good architecture over the life of a project takes a lot of effort. You have to treat your codebase like a good camper does their campsite: always try to leave it a little better than you found it.
• Design requires a lot of experimentation and exploration. Especially early on, it’s common to write code that you know you’ll throw away.
• If there is any method that eases these constraints, it’s simplicity. In my code today, I try very hard to write the cleanest, most direct solution to the problem. The kind of code where after you read it, you understand exactly what it does and can’t imagine any other possible solution.

[Juan F Gonzalez]

High quality code is the one that has a low wtf/hour ratio

[Casey Brooks]

😅

[Martin Häusler]

This is the one and only true metric for good code quality. It never fails.

[Juan F Gonzalez]

Exactly so, although I think that per minute would be a really big number hahaha.

[Julia Torrejón]

An interesting point from Gridshore on this:

The most effective and certain method, however, is the code review. However, it is also very time consuming. It requires that one or more developers restrain from being (in the eyes of the customer) productive and give their attention to someone else’s code. Provided that the developer has a high standard of quality, it will definitely improve total quality of the code. Of course, there is the concept of pair programming, which could be seen as a form of continuous code reviewing. Highly effective, and can improve the skills of both developers.

These tools and processes can be very useful, but their overall efficiency depends on one thing: quality awareness within your development team. I’ll explain what I mean with “quality awareness”. It is the ability of developers to recognize code smells or failure to use design patterns at locations where they would typically be applied. This awareness it typically raises as developers gain more experience, but we’d typically like to help fate a little hand.

[jeikabu]

Definition:

• More theoretical ideal; perfection is not attainable
• "Good" implies partially subjective
• Not binary.; there are many states in-between
• Not absolute; varies over time

Attributes:

• Well designed without being over-engineered
• State of the art, but not obscure or overtly clever
• Documented, but no superfluous comments
• Reviewed and refactored within time-constraints
• Optimal in time and space while avoiding premature optimization
• Meets business/technical requirements and common sense
• Leverages tools of the trade (testing, static analysis, etc.) if/when appropriate
• Maintainable and extendable in accord to its purpose

It's like art vs obscenity; I know it when I see it.

[Julia Torrejón]

• Reviewed and refactored within time-constraints

So, what would be the optimal time? Or is it somehow subjective depending on the circumstances?

[jeikabu]

It's subjective and variable depending on the circumstances:

• Skill and experience of the author (I tend to gloss over PRs by people that do consistently good work)
• Difficulty/importance of changes
• ROI for additional time spent etc.

There's an implicit assumption that you can't spend "forever" on a piece of code; at some point it's got to be "good enough" so you can move on. It's also subject to diminishing returns.

[Truong Hoang Dung]

To me, high quality code means less lines of code, but has more power. That power might be a useful abstraction, or it's just a useful algorithm to solve repeatable problems.
And if you want more quality of your code, make it easy to test, the easier to test a code block, the more quality that code block has.
And if you want even more quality of your code, make it fast. If your language couldn't make it fast enough, change the language.

[Julia Torrejón]

How can you make your code faster?

[Truong Hoang Dung]

"Make it fast" means you should use better algorithms or data structures to solve the problem. Because as you know, to solve one problem, there're many ways to do it. So it's also called optimization of the code to use better libraries, for example.

[Michael Cain]

Personally, the more that code reads like prose, the higher quality it is. High quality code tells you the story about the business solution that it is implementing.

My favorite code is that which reveals to me something about the business that I did not previously know. Plus, like businesses, it’s written in a way to accommodate the future only when the future arrives.

[Ryan]

Maintainable and efficient.

Maintainable means it is easy to understand, sensibly organized, it is painless to make modifications that should be expected (client wants to add another type of report), and as easy as possible to make changes that aren't (client wants a totally new feature)

Efficient means the code uses as few resources as possible to accomplish its job, so that it is as fast and scalable as possible.

[Julia Torrejón]

Uncle Bob says:

The answer to clean code is craftsmanship.

There are two parts to learning craftsmanship: knowledge and work. You must gain the knowledge of principles, patterns, practices and heuristics that a craftsman knows, and you must also grind that knowledge into your eyes and gut by working hard and practicing.

Learning to write clean code is hard work. It requires more than just the knowledge of principles and patterns. You must sweat over it. You must practice it yourself, and watch yourself fail. You must watch others practice it and fail, You must see them stumble and retrace their steps.

That is good advice for a beginner!

[tux0r]

It is written in C.

[Julia Torrejón]

Could you explain why?

[Alain Van Hout]

I'm going to use the #likeimfive approach here.

If code is like cake, then good code is like cake that you can enjoy eating and that will not leave you with stomach aches later on.

Note that 'doing what it is supposed to' is not an attribute of good code any more than 'being edible' is an attribute of good cake. That's just a fundamental real-world requirement for when someone asks you to write code / bake a cake. It doesn't have anything to do with either of those being good.

[Camilla Santiago]

Just to highlight.. so you mean cake is considered good based on the experience of eating it.

[Alain Van Hout]

In the case of cake, yes. How that translates to code is that code is also experienced as being good by how you interact with it later, i.e. modifying it in any way (rather than just looking at it).

[Heiker]

In my opinion "good" code is the one that is disposable. Is a codebase where you can identify with confidence the parts that need to be changed or removed in order to make a new feature or meet a new requirement.

You won't necessarily recognize it when you see it or when you write it for the first time, but you'll know when the times comes and you have to mantain it.

[Florian Rohrer]

My personal definition is very subjective: A code is of high quality if

• someone other than the author can read and understand it, without investing too much time and coginitive effort
• it follows the conventions of your field (using familiar variable names, familiar abbreviations, familiar unit systems), whatever they might be.
• and one thing (source file / class / package) solves one task.

[Thomas Junkツ]

High quality code is code written by someone who cares.

What does it mean to care?

• Knowing the language beyond the syntax, i.e. writing concise ideomatic code

• Naming things in a way which helps understanding the purpose of things

• Grouping things together, which belong together

Or as Ward Cunningham once put it:

You know you are working with clean code when each routine you read
turns out to be pretty much what you expected. You can call it beautiful
code when the code also makes it look like the language was made for the problem.

I heared once, that instead of naming it »software engineering« it should be renamed to »software gardening«. This would connotate the constant effort which has to be put into a codebase in order to keep it beautiful and keep weeds at a minimum.

[Nested Software]

I’ll chime in with some characteristics I try to impart to my code:

• simple: keep the code as simple as possible. Avoid over-engineering.
• readable: make the intent of the code as clear as possible.
• orthogonal: give modules of code clear and independent responsibilities. Ideally modules that work together should be composable in any combination.
• tested: code should have automated tests by default.
• graceful with errors: modules should have well thought out considerations for edge cases and error conditions.

[Casey Brooks]

The projects I've worked with that had the best codebase to them actually made it difficult to write bad code with it. Bad code typically comes when there is too much going on and it is not well abstracted, so developers have trouble understanding it and end up writing more bad code, making the problem even worse.

In contrast, a good codebase has very clearly-defined structures and well-architected patterns that guide you toward the solution intended by its creators.

For example, Laravel was created for a specific purpose, and every API it opens up to developers drives you right where it wants you. You really have to put in a lot of work to use Laravel in any way other than it was designed for, and the way it encourages you to develop in it feels very natural and clean. The underlying codebase of Laravel is what I consider to be the best codebase I've ever seen and worked with.

Comparatively, Android's codebase is a bit of a mess. Don't get me wrong, I love Android and it is my favorite platform to develop for, but its codebase is messy and confusing, needlessly complex, often contradictory, and with very little direction given to the developer. It is definitely getting better now that it has matured the core framework, with Google starting to focus on better APIs for UI components and a more opinionated approach with Jetpack, but I still struggle to understand how most of the internal classes work, no matter how long I study their code.

[Julia Torrejón]

Therefore, a good codebase is the base of good code, isn't it? :)

[zeddotes]

That's not necessarily true in all cases.

You write code as language for a computer. When you speak to another person, whether it's functional or an expression, you can say it in multiple ways -- all accomplishing the same task, in bad, good, great, and best ways. "Accomplishes the task" is ambiguous, as is the task's definition. For example, a task to display an RSS feed on a page is different for a junior dev vs an intermediate, or even another junior dev. It's very well different for different types of people, roles, cultures, etc.

Code quality measurement is like checking someone's health. If your life purpose was defined with 100% accuracy and our biotech was 100% accurate could one accurately determine a person's health exactly. Because we're far from that point, we make estimations based on multiple dimensions like weight, height, sugar levels, etc; similarly, we have test coverage, penetration/smoke testing, analytics, user group sessions, etc.