🔒 How to Make an Immutable Class in Java (Step-by-Step Guide)

Learn how to create an immutable class in Java with real-world examples. Understand why immutability matters, and follow best practices to design robust, thread-safe objects.

What is an Immutable Class?

In Java, an immutable class is a class whose objects cannot be modified after they are created.

Once an object is created, its state (data) stays the same forever.

Popular example?
➡️ String in Java is immutable.

💡 Real-world Analogy:

A date of birth is immutable. Once set, it should never change.

🤔 Why Create Immutable Classes?

Here’s why developers love immutability:

Famous Immutable Classes in Java

• String
• Integer
• BigDecimal
• LocalDate, LocalTime (Java 8 Time API)

Ever wondered why String is immutable? Because it's used everywhere — making it immutable ensures safety and efficiency.