How can you improve code quality and readability without changing functionality?

It's really important to balance algorithm efficiency and code readability in a any project. You can follow few of these ways we do follow for any project to improve code readability without sacrificing efficiency or changing functionality. 1. Use meaningful variable, functions and methods naming. 2. Use comments wherever needed especially when you're doing some complex operations (Also, avoid super obvious comments). 3. Use widely used coding principles and standards like: SOLID principle 4. Use the DRY principle (Do not Repeat Yourself) 5. Refactor big chunks of code into small components. 6. Use best practices for file and folder organizations. 7. Use some code formatting tools like Prettier or ESLint.

It's important to have standard code formatting, so code can be easily read by other developers. Some of our rules: - indentation should use 4 spaces - if 1 line of code became too long, break it into multiple lines (IDE usually have indicator of where the code should wrap) - new line for every function call, a.getA() .some() .function() .other() - when checking nested attribute, always check null for every methods, and if there are more than 2 methods call, split it into multiple ifs: Instead of "if (null != a && null != a.getB() && null != a.getB().getC() && null != a.getB().getC().getD())" Write it like this if (null != a && null != a.getB() && null != a.getB().getC()) ....var c= a.getB().getC() ....if (null != c && null != c.getD())

Refactoring can be surely make the code easier to read. Many developers surely have that time when the schedule is tight, backlog is a mountain, deadline is so near that they just code to make the code run and can be executed, without looking wether that code is duplicate, or that code is readable. After that storm passed, backlog is very low, one may find their previous code are not on par with the standards, so they did refactoring to make their code better. Most common refactoring that we did was extracting some logic from the methods because it actually is a code duplication. Some other refactoring was rewriting the logics, because sometimes one create too complex logic for not so complex problem.

Comments that are most important for us were the method doc (javadoc, jsdoc, etc). When developer create a new function or method, they have to create the doc with clear explanation of what that method does, what are the parameters, what are they used for, and what are the returns (if any), or what will the method thrown if there are some exception. Comments inside methods are allowed if the methods are too complex and it's hard to explain it in the doc. If the explanation can be put inside the doc, then comments inside the methods are unnecessary.

Naming of the variables and methods should be as short as possible but as descriptive as possible. Don't use variable names like a, b, or other non meaningful names as it will make it harder for other developers to understand the code, although sometimes it's ok to have meaningless names in code, as long as the context is clear, for example in a simple for each, that will only have that attributes in play.

You code, you surely did testing, whether it's manual testing or using unit test or integration test. Unit test and integration test are important, because it can spot if some of our modification will cause an error to existing feature. And if there's some error while testing, debugging where the error was thrown can spot what when wrong.