Is Java Case Sensitive? (Java Interview Question and Answer)

Ramesh Fadatare

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Mar 21, 2025

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Java developers — especially beginners — often come across this common interview question:

“Is Java case sensitive?”

Let’s explore the answer in detail with examples to help you understand it clearly.

✅ Quick Answer

Yes, Java is a case-sensitive programming language.

This means uppercase and lowercase letters are treated as different. So, for example, MyClass and myclass are not the same in Java.

📌 What Does Case Sensitivity Mean?

Case sensitivity refers to the ability of a programming language to differentiate between uppercase and lowercase letters in identifiers like:

• Class names
• Variable names
• Method names
• Keywords

🔍 Java Case Sensitivity in Action

Let’s take a look at some simple examples to see how Java treats uppercase and lowercase characters.

💡 1. Class Names

public class MyClass {
    public static void main(String[] args) {
        System.out.println("Hello Java");
    }
}

✅ The class is correctly named MyClass.

But what if you save the file as myclass.java?

❌ You’ll get a compilation error:

Error: class MyClass is public, should be declared in a file named MyClass.java

💡 2. Variable Names

int number = 10;
System.out.println(Number); // ❌ Error!

Explanation: number and Number are two different identifiers.

💡 3. Method Names

public void printData() {
    System.out.println("Data");
}

printdata(); // ❌ This will throw an error: method not found

Again, printData() ≠ printdata()

💡 4. Java Keywords

Even keywords are case-sensitive in Java.

Public class Test { } // ❌ Error: 'Public' is not a recognized keyword

Only public (all lowercase) is a valid keyword.

🧠 Why Is Java Case Sensitive?