I’ve been programming with Java for a few years now but one of the first questions I had when first learning it was; “Is Java case-sensitive?”
This actually tripped me up quite a bit when I was a beginner. I kept running into compile errors and I didn’t know why. I know I’m not the only one out there who struggled with this question so let’s answer it now once and for all.
Is Java Case Sensitive?
Java is a case-sensitive programming language. For example, if a variable is named ‘HelloWorld‘, then there will be a compilation error if the variable is called ‘helloworld‘. Variables and objects in Java must be called exactly how they are named, including the case.
Here, we’ll discuss how java is case sensitive and what to do to prevent mistakes in coding. So, read this article until the end and you’ll find it helpful.
What Does It Mean To Be Case Sensitive?
Before going into details of Java’s case-sensitive nature, it is essential to understand the meaning of the term case-sensitive.
Case-Sensitive: Any computer function or a program that differentiates between upper and lowercase letters is called a case-sensitive program.
Moreover, in case-sensitive programs, the input is treated differently.
Some examples of case-sensitivity are Desktop and desktop. In the first one, D is capital, and in the second one, d is lowercase. Modern systems are case-sensitive, and they give either run time error or show file name doesn’t match or incorrect.
Let’s look at some more examples so that we can be perfectly clear in our understanding.
Example of Java Case Sensitivity
In all programming languages, you need to provide exact values in order to get the desired results.
For example, in java, x isn’t X, and it will change the output as well.
To clarify, let’s look at a simple example of printing a name. I first declare two variables, one for the first name (firstName) and one for the last name (lastName).
Notice these two variables use the camelCase naming convention.
However, in the example below, when I call these variables I don’t type out the variable name exactly as I did when I created them.
// Example of INCORRECT use of case sensitivity in JavaString firstName = "Tim"; String lastName = "Statler"; System.out.println("My name is " + firstname + " " + lastname);
This is an example of ignoring Java’s rule on case-sensitivity, which will lead to a compile error.
In order to avoid this, simply type the variable’s name exactly as it was spelled when it was created, including the case!
This is the proper way to call the variables:
// Example of CORRECT use of case sensitivity in JavaString firstName = "Tim"; String lastName = "Statler"; System.out.println("My name is " + firstName + " " + lastName);
For more information on creating and using strings in Java, visit Oracle’s website which has a short guide for exactly such.
Why Is Case Important in Java?
We all get frustrated when our programs don’t run correctly.
When you use a wrong case, it matters at the level of bits and bytes. For the computer, it isn’t a matter of wanting to sabotage your program. It simply needs the right directions given to it in order to operate as intended.
When you call a variable, you are giving the computer directions. However, when you try to call the variable lastName but instead you type lastname, you’ll get a compile error. This is because both these letters (N and n) have different values in memory.
The best practice is to name variables consistently. The standard method for variable names is to use lowercase letters and camelCase.
camelCase allows you to use uppercases to improve the readability. For example, pageNum and treeCount. You can name classes with uppercase, such as Vehicle, Tree, and Game.
Java is based on programming languages like C++ and C, but all the programming languages are not case sensitive. Languages that don’t enforce case-sensitivity are COBOL, FORTRAN, Pascal, and other primary languages.
Why Is Java Case Sensitive?
In most programming languages and environments, case-sensitivity is the norm.
Both upper and lower case letters are represented differently at the lowest levels. For computers, cases are completely different and computers have to do extra work to make them work the same.
Furthermore, different programming languages have tricky and special rules for the casing. Java is case-sensitive because of its heritage from the C language. Additionally, it uses C-style syntax; therefore, it’s case-sensitive.
Reasons Why Java Is Case Sensitive
There are plenty of reasons that explain why Java is case sensitive, such as:
- Java is widely used for developing codes, and it contains different variables that make it case sensitive. Moreover, it’s a platform-independent language.
- Java is used in different machines, regardless of platform. Therefore it must be case sensitive.
- Case sensitivity also makes Java a more flexible language. Using a different case in the main and sub-programs makes it easier to understand.
- In Java, different functions and keywords are used. Java’s case sensitive nature also adds to its security.
- In the Java programming language, you won’t get the correct results when you enter all commands in uppercase. It’s one of those programming languages that are case sensitive because it will show different results for commands Run and run.
Tips for Avoid Case Sensitivity Errors in Java
When coding in java, follow the below-given tips to avoid errors:
- Don’t use variables that only differ in case. For example, when you have three variables named Endloop, EndLoop, and endLoop. You can mistype these variable names anytime. As a result, you’ll find that code has changed the value of the wrong variable.
- In java, keywords are always written in lowercase. A full list of java keywords is available in the reserved words list found on Oracle’s website here.
- Always ensure that the java file name and class name match. If the file name and class name do not match, your program will not compile and you’ll receive a compile error.
- Java naming conventions can help you avoid typing mistakes. It can help you if you have naked of using the same case for different identifier types.
- When you use a string to represent pathname, ensure that you use the right case. Some programs on the operating system are sensitive, and they give runtime errors or show that filename doesn’t exist.
Is Java case-sensitive? Yes, it is. We have covered different reasons in detail. Moreover, you can find some useful tips in this article so that you can avoid programming errors in Java.
If you want to learn how to program with Java, check out these 10 awesome Java projects for beginners. There is a full video tutorial that walks you through each project, step-by-step. And it’s absolutely FREE!