5 Common Java Coding Mistakes to Avoid

Woman working on code

Java is a strong and versatile programming language. Most tech companies generally expect that the computer programmers they hire will know how to use Java, so you’ll definitely want to focus on it while you work toward your degree. As with learning any new programming language, you’ll be able to pick up on its nuances better by practicing coding as you learn. Be sure to watch out for these common mistakes.

1. Forgetting that Java is case-sensitive.

Some languages still in use today are case-insensitive. Two examples are HTML and SQL. If you’re accustomed to using either of these languages, you might need to remind yourself occasionally that Java is indeed case-sensitive. All of Java’s keywords are lowercase. For example, an “if” statement cannot be an “If” or “IF” statement. Additionally, remember to maintain consistency with lowercase or uppercase in the names you create. If you use multiple versions of a variable name, Java will consider it to be different names entirely.

2. Comparing values inappropriately.

It can be tempting to use a single equal sign when writing two values. Unfortunately, Java won’t forgive this. Always use a double equal sign. For example, write “if (inputNumber == randomNumber).”

3. Missing a break in a switch case construct.

This is one of the most common mistakes that beginning Java programmers make. It won’t result in a compile error, but it will cause the code to run improperly. This mistake is often not detected until running the program, which will create some debugging headaches. Missing a break in Java is problematic because this language has a feature called fall through. If there’s no break in the current case, fall through causes the code execution to simply continue on to the next case.

4. Neglecting to declare identifiers before using them.

Java requires you to declare all identifiers before you use them. If you forget this step, you’ll get the “cannot find symbol” error message. This error message might also be due to discrepancies in the spelling of the identifier as expressed when it was declared versus when it was used. Other possibilities are that the class was not imported or that the variable isn’t used in the same scope as it was declared.

5. Using a switch statement as an unnecessary replacement to an “if…else” statement.

The switch statement works by going through all of the various cases to find the right one. All of the cases will be tested. This isn’t necessarily an egregious mistake, but overuse of the switch statement can suggest poor object orientation. Instead, if an “if…else” statement will work, go ahead and use it. As an added perk, Java developers typically find that “if…else” statements are easier to read.

You can hone your computer programming skills as a student at the College of Science, Engineering, and Technology. Grand Canyon University is pleased to offer our Bachelor of Science in Computer Programming class, which explores Java, SQL, and C#. Click on Request More Information to begin working toward your rewarding career in computer programming!

The views and opinions expressed in this article are those of the author’s and do not necessarily reflect the official policy or position of Grand Canyon University. Any sources cited were accurate as of the publish date.