Robert C. Martin Quotes & Sayings

When you are working on a problem, you sometimes get so close to it that you can't see all the options. You miss elegant solutions because the creative part of your mind is suppressed by the intensity of your focus. Sometimes the best way to solve a problem is to go home, eat dinner, watch TV, go to bed, and then wake up the next morning and take a shower. — Robert C. Martin

God is in the details, said the architect Ludwig mies van der Rohe. — Robert C. Martin

If the discipline of requirements specification has taught us anything, it is that well-specified requirements are as formal as code and can act as executable tests of that code! — Robert C. Martin

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. You must see them agonize over decisions and see the price they pay for making those decisions the wrong way. — Robert C. Martin

Encapsulation is broken because all functions in the path of a throw must know about details of that low-level exception. Given that the purpose of exceptions is to allow you to handle errors at a distance, it is a shame that checked exceptions break encapsulation in this way. — Robert C. Martin

Clean code can be read, and enhanced by a developer other than its original author. It has unit and acceptance tests. It has meaningful names. It provides one way rather than many
ways for doing one thing. It has minimal dependencies, which are explicitly defined, and provides a clear and minimal API. Code should be
literate since depending on the language, not all necessary information can be expressed clearly in code alone.

-Dave Thomas, founder
of OTI, godfather of the
Eclipse strategy — Robert C. Martin

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 fingers, eyes, and gut by working hard and
practicing. — Robert C. Martin

The perfect kind of architecture decision is the one which never has to be made — Robert C. Martin

Good software designs accommodate change without huge investments and rework. When we use code that is out of our control, special care must be taken to protect our investment and make sure future change is not too costly. — Robert C. Martin

Clean code is not written by following a set of rules. You don't become a software craftsman by learning a list of heuristics. Professionalism and craftsmanship come from values that drive disciplines. — Robert C. Martin

Objects hide their data behind abstractions and expose functions that operate on that data. Data structure expose their data and have no meaningful functions. — Robert C. Martin

Procedural code (code using data structures) makes it easy to add new functions without changing the existing data structures. OO code, on the other hand, makes it easy to add new classes without changing existing functions. — Robert C. Martin

A long descriptive name is better than a short enigmatic name. A long descriptive name is better than a long descriptive comment. — Robert C. Martin

You should choose a set of simple rules that govern the format of your code, and then you should consistently apply those rules. If you are working on a team, then the team should agree to a single set of formatting rules and all members should comply. — Robert C. Martin

The hardest thing about choosing good names is that it requires good descriptive skills and a shared cultural background. This is a teaching issue rather than a technical, business, or
management issue. — Robert C. Martin

If your function must change the state of something, have it change the state of its owning object. — Robert C. Martin

it's confusing to have a controller and a manager and a driver in the same
code base. What is the essential difference between a DeviceManager and a Protocol-Controller? Why are both not controllers or both not managers? Are they both Drivers really? The name leads you to expect two objects that have very different type as well as
having different classes.

A consistent lexicon is a great boon to the programmers who must use your code. — Robert C. Martin

Redundant comments are just places to collect lies and misinformation. — Robert C. Martin

Programmers must avoid leaving false clues that obscure the meaning of code. — Robert C. Martin

the ratio of time spent reading vs. writing is well over 10:1. — Robert C. Martin

Resisting premature abstraction is as important as abstraction itself. — Robert C. Martin

The only way to prove that your software is easy to change is to make easy changes to it. And when you find that the changes aren't as easy as you thought, you refine the design so that the next change is easier. When do you make these easy changes? All the time! Every time you look at a module you make small, lightweight changes to it to improve its structure. — Robert C. Martin

I like my code to be elegant and efficient. The logic should be straightforward to make it hard
for bugs to hide, the dependencies minimal to ease maintenance, error handling complete according to an articulated strategy, and performance
close to optimal so as not to tempt
people to make the code messy with unprincipled optimizations. Clean code does one thing well.

-Bjarne Stroustrup, inventor of C++
and author of The C++ Programming
Language — Robert C. Martin

Few practices are as odious as commenting-out code. Don't do this! — Robert C. Martin

You see, programmers tend to be arrogant, self-absorbed introverts. We didn't get into this business because we like people. Most of us got into programming because we prefer to deeply focus on sterile minutia, juggle lots of concepts simultaneously, and in general prove to ourselves that we have brains the size of a planet, all while not having to interact with the messy complexities of other people. — Robert C. Martin

To write clean code, you must first write dirty code and then clean it. — Robert C. Martin

When you see commented-out code, delete it! — Robert C. Martin

Building a project should be a single trivial operation. — Robert C. Martin

Code, without tests, is not clean. No matter how elegant it is, no matter how readable and accessible, if it hath not tests, it be unclean. Dave — Robert C. Martin

It is not the language that makes programs appear simple. It is the programmer that make the language appear simple! — Robert C. Martin

So if you want to go fast, if you want to get done quickly, if you want your code to be easy to write, make it easy to read. — Robert C. Martin

Writing clean code is what you must do in order to call yourself a professional. There is no reasonable excuse for doing anything less than your best. — Robert C. Martin

It is a myth that we can get systems "right the first time." Instead, we should implement only today's stories, then refactor and expand the system to implement new stories tomorrow. This is the essence of iterative and incremental agility. Test-driven development, refactoring, and the clean code they produce make this work at the code level. — Robert C. Martin

QA and Development should be working together to ensure the quality of the system. The — Robert C. Martin

The first rule of functions is that they should be small. The second rule of functions is that they should be smaller than that. — Robert C. Martin

It is unit tests that keep our code flexible, maintainable, and reusable. The reason is simple. If you have tests, you do not fear making changes to the code! Without tests every change is a possible bug. — Robert C. Martin

(refactored) /** — Robert C. Martin

These comments are so noisy that we learn to ignore them. As we read through code, our eyes simply skip over them. Eventually the comments begin to lie as the code around them changes. — Robert C. Martin

Honesty in small things is not a small thing. — Robert C. Martin

The problem isn't the simplicity of the code but the implicity of the code (to coin a phrase): the degree to which the context is not explicit in the code itself. — Robert C. Martin

Truth can only be found in one place: the code. — Robert C. Martin

Whatever else a TODO might be, it is not an excuse to leave bad code in the system. — Robert C. Martin

Try to write tests that force exceptions, and then add behavior to your handler to satisfy your tests. This will cause you to build the transaction scope of the try block first and will help you maintain the transaction nature of that scope. — Robert C. Martin

Say what you mean. Mean what you say. — Robert C. Martin

Of course bad code can be cleaned up. But it's very expensive. — Robert C. Martin

Indeed, the ratio of time spent reading versus writing is well over 10 to 1. We are constantly reading old code as part of the effort to write new code. ...[Therefore,] making it easy to read makes it easier to write. — Robert C. Martin

Nothing has a more profound and long-term degrading effect upon a development project than bad code. Bad schedules can be redone, bad requirements can be redefined. Bad team dynamics can be repaired. But bad code rots and ferments, becoming an inexorable weight that drags the team down. — Robert C. Martin

Clean code always looks like it was written by someone who cares. — Robert C. Martin

Returning null from methods is bad, but passing null into methods is worse. — Robert C. Martin

You know you are working on clean code when each routine turns out to be pretty much what you expected." Half — Robert C. Martin

The topmost parts of the source file should provide the high-level concepts and algorithms. Detail should increase as we move downward, until at the end we find the lowest level functions and details in the source file. — Robert C. Martin

Duplication may be the root of all evil in software. Many principles and practices have been created for the purpose of controlling or eliminating it. — Robert C. Martin

That these acts are simple doesn't mean that they are simplistic, and it hardly means that they are easy. — Robert C. Martin

You are reading this book for two reasons. First, you are a programmer. Second, you want to be a better programmer. Good. We need better programmers. — Robert C. Martin

One of the best ways to ruin a program is to make massive changes to its structure in the name of improvement. Some programs never recover from such "improvements." The problem is that it's very hard to get the program working the same way it worked before the "improvement. — Robert C. Martin

Cuteness in code often appears in the form of colloquialisms or slang. For example, don't use the name whack() to mean kill(). Don't tell little culture-dependent jokes like eatMyShorts() to mean abort().
Say what you mean. Mean what you say. — Robert C. Martin

...creative output depends on creative input. — Robert C. Martin

What this team did not realize was that having dirty tests is equivalent to, if not worse than, having no tests. — Robert C. Martin

Professionals use their powers for good and write code that others can understand. — Robert C. Martin

Who can justify the expense of a six-lane highway through the middle of a small town that anticipates growth? Who would want such a road through their town? — Robert C. Martin

Indeed, most of us realize that the requirements are the most volatile elements in the project. — Robert C. Martin

A system that is comprehensively tested and passes all of its tests all of the time is a testable system. That's an obvious statement, but an important one. Systems that aren't testable aren't verifiable. Arguably, a system that cannot be verified should never be deployed. — Robert C. Martin

Duplication and expressiveness take me a very long way into what I consider clean code, and improving dirty code with just these two things in mind can make a huge difference. There is, however, one other thing that I'm aware of doing, which is a bit harder to explain. — Robert C. Martin

In an ideal system, we incorporate new features by extending the system, not by making modifications to existing code. — Robert C. Martin

Why do most developers fear to make continuous changes to their code? They are afraid they'll break it! Why are they afraid they'll break it? Because they don't have tests. — Robert C. Martin

The LSP makes clear that in OOD the ISA relationship pertains to behavior. Not intrinsic private behavior, but extrinsic public behavior; behavior that clients depend upon. — Robert C. Martin

What would happen if you allowed a bug to slip through a module, and it cost
your company $10,000? The nonprofessional would shrug his shoulders, say
"stuff happens," and start writing the next module. The professional would
write the company a check for $10,000! — Robert C. Martin

Slaves are not allowed to say no. Laborers may be hesitant to say no. But
professionals are expected to say no. Indeed, good managers crave someone who
has the guts to say no. It's the only way you can really get anything done. — Robert C. Martin

If its dependencies are inverted, it has an OO design. If its dependencies are not inverted, it has a procedural design. — Robert C. Martin

How can we make sure we wind up behind the right door when the going gets tough? The answer is: craftsmanship. — Robert C. Martin

You should be able to run all the unit tests with just one command. — Robert C. Martin

The complement is also true: Procedural code makes it hard to add new data structures because all the functions must change. OO code makes it hard to add new functions because all the classes must change. — Robert C. Martin

Programming is a social activity. — Robert C. Martin

Error handling is important, but if it obscures logic, it's wrong. — Robert C. Martin

Code formatting is important. It is too important to ignore and it is too important to treat religiously. Code formatting is about communication, and communication is the professional developer's first order of business. — Robert C. Martin

It is not enough for code to work. — Robert C. Martin

The majority of the cost of a software project is in long-term maintenance. — Robert C. Martin

LeBlanc's law: Later equals never. — Robert C. Martin

Perhaps you thought that "getting it working" was the first order of business for a professional developer. I hope by now, however, that this book has disabused you of that idea. The functionality that you create today has a good chance of changing in the next release, but the readability of your code will have a profound effect on all the changes that will ever be made. — Robert C. Martin

if I must encode either the interface or the implementation, I choose the implementation. Calling it ShapeFactoryImp, or even the hideous CShapeFactory, is preferable to encoding the interface. — Robert C. Martin

Am I suggesting 100% test coverage? No, I'm not suggesting it. I'm demanding it. Every single line of code that you write should be tested. Period. — Robert C. Martin

The fact that the task to write perfect software is virtually impossible does not mean you aren't responsible for the imperfection. — Robert C. Martin

You should name a variable using the same care with which you name a first-born child. — Robert C. Martin

If you let the tests rot, then your code will rot too. Keep your tests clean. — Robert C. Martin

Remember that code is really the language in which we ultimately express the requirements. We may create languages that are closer to the requirements. We may create tools that help us parse and assemble those requirements into formal structures. But we will never eliminate necessary precision - so there will always be code. — Robert C. Martin

Duplication is the primary enemy of a well-designed system. — Robert C. Martin

If you're good at the debugger it means you spent a lot of time debugging. I don't want you to be good at the debugger. — Robert C. Martin