Java 18: What’s New and Why You Should Care

Java 18, the latest version of the Java programming language, brings several exciting features and enhancements that aim to improve developer productivity, performance, and security. In this blog post, we will explore the key additions in Java 18 and discuss why you should care about upgrading to this version.

  1. Pattern Matching for Switch (Preview Feature):
    One of the most significant features introduced in Java 18 is the enhancement of pattern matching for switch statements. This allows for more expressive and concise code when working with complex data structures and patterns.

Example:

int statusCode = 404;

String result = switch (statusCode) {
    case 200 -> "Success";
    case 404 -> "Page not found";
    case 500 -> "Internal server error";
    default -> "Unknown status code";
};

System.out.println(result); // Output: Page not found

Pattern matching for switch simplifies the code by eliminating the need for repetitive variable assignment or break statements.

  1. Sealed Classes (Preview Feature):
    Java 18 introduces sealed classes, which provide more control over class inheritance and enhance encapsulation. Sealed classes restrict which classes can extend or implement them, promoting better API design and preventing unauthorized extensions.

Example:

public sealed class Shape permits Circle, Rectangle, Triangle {
    // Common properties and methods
}

public final class Circle extends Shape {
    // Circle-specific implementation
}

public final class Rectangle extends Shape {
    // Rectangle-specific implementation
}

// Triangle class omitted for brevity

By using sealed classes, you can explicitly define which subclasses are allowed, making your code more maintainable and secure.

  1. Vector API (Incubator Feature):
    Java 18 introduces the Vector API as an incubator feature, providing a uniform and efficient way to perform vector computations on arrays. This feature leverages modern hardware capabilities, such as SIMD (Single Instruction, Multiple Data), to achieve high-performance parallel processing.

Example:

import jdk.incubator.vector.*;

public class VectorExample {
    public static void main(String[] args) {
        try (var scope = VectorOperators.createScope()) {
            var vectorA = VectorSpecies.of(int.class).laneCount();
            var vectorB = VectorOperators.broadcast(vectorA, 10);
            var vectorC = VectorOperators.broadcast(vectorA, 5);

            var result = VectorOperators.add(vectorA, VectorOperators.mul(vectorB, vectorC));

            System.out.println(result);
        }
    }
}

The Vector API simplifies the development of performance-sensitive code, enabling developers to harness the power of vectorized operations.

  1. Enhanced Patterm Matching for instanceof (Preview Feature):
    Java 18 extends the pattern matching capabilities by enhancing the instanceof operator. It allows you to combine type checks and object binding in a single expression, reducing boilerplate code and enhancing readability.

Example:

if (obj instanceof String s && s.length() > 5) {
    System.out.println("String length is greater than 5");
}

The enhanced instanceof simplifies the code by introducing a new binding variable s, which represents the casted object if the type check succeeds.

Why You Should Care:
Upgrading to Java 18 offers several benefits:

  • Improved productivity: Features like pattern matching for switch and enhanced instanceof reduce code verbosity and enhance expressiveness, leading to more readable and maintainable code.
  • Enhanced performance: The Vector API empowers developers to leverage modern hardware capabilities for high-performance computing, resulting in faster and more efficient operations.
  • Better security and encapsulation: Sealed classes provide stricter control over class inheritance, ensuring that only authorized subclasses can be created, thus enhancing API design and preventing unauthorized extensions.


Java 18 introduces exciting features that enhance developer productivity, performance, and security. Features like pattern matching for switch, sealed classes, the Vector API, and enhanced instanceof simplify code, improve performance, and provide better control over class inheritance. Upgrading to Java 18 enables developers to leverage these new features and stay at the forefront of Java development. So, embrace the power of Java 18 and take advantage of its enhancements to build robust and efficient applications.

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