Java 14 Features

1. 🔹 Switch Expressions (Standard Feature – JEP 361)

After being in preview in Java 12 and 13, switch expressions became official in Java 14.

Example:

String day = "MONDAY";

int result = switch (day) {
    case "MONDAY", "FRIDAY" -> 6;
    case "TUESDAY" -> 2;
    default -> 0;
};

System.out.println(result); // Output: 6

✅ Enables switch to return values and prevents fall-through errors.

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2. 🔹 Text Blocks (2nd Preview – JEP 368)

Multi-line string literals continue to improve with feedback from Java 13.

Example:

String json = """
    {
        "name": "Java",
        "version": 14
    }
    """;
System.out.println(json);

Use --enable-preview flag to run this in Java 14.

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3. 🔹 Records (Preview – JEP 359)

A record is a new kind of class in Java meant to model immutable data. It automatically generates equals(), hashCode(), toString(), and a constructor.

Example:

record Person(String name, int age) {}

public class Main {
    public static void main(String[] args) {
        Person p = new Person("Alice", 30);
        System.out.println(p.name()); // Alice
        System.out.println(p);        // Person[name=Alice, age=30]
    }
}

✅ Great for DTOs or simple data holders.

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4. 🔹 Pattern Matching for instanceof (Preview – JEP 305)

Reduces boilerplate code for instanceof type checking and casting.

Before Java 14:

if (obj instanceof String) {
    String s = (String) obj;
    System.out.println(s.length());
}

Java 14 (Preview):

if (obj instanceof String s) {
    System.out.println(s.length());
}

✅ Cleaner and less error-prone.

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5. 🔹 Helpful NullPointerExceptions (JEP 358)

The JVM now provides detailed messages showing which variable was null in a chain.

Example Output:

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "Address.getCity()" because "user.getAddress()" is null

✅ Major improvement for debugging nulls!

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6. 🔹 Foreign-Memory Access API (Incubator – JEP 370)

Provides a way to safely and efficiently access memory outside the Java heap — like native memory.

Useful for high-performance applications or integrations with C libraries.

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7. 🔹 ZGC and Shenandoah GC Improvements

• ZGC now supports all Linux/x64 configurations.
• Shenandoah is integrated with JDK builds (no longer external).

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🔚 Summary Table

Feature	Description	Status
Switch Expressions	Return values from switch	✅ Final
Text Blocks	Multi-line strings	🧪 Preview 2
Records	Immutable data classes	🧪 Preview
Pattern Matching (instanceof)	Inline type cast in condition	🧪 Preview
Helpful NPEs	Clear null pointer messages	✅ Final
Foreign Memory Access	Off-heap memory access	🔬 Incubator
ZGC & Shenandoah	GC improvements	✅ Final

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📝 Note:

• Features like Records, Pattern Matching, and Text Blocks require --enable-preview in Java 14.