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Gopi Gorantala

I'm Gopi — 15+ years in Java, building Kafka and Flink platforms for banks, where one lost event is a financial discrepancy. I write javahandbook.com because the guides I needed didn't exist. Everything here is tested against a real cluster first.

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What is Declarative Programming? With Examples

In this lesson, you will learn declarative programming and the steps to achieve it. You will also be introduced to some real-world use cases for easy understanding.

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What Are The 3 Types Of Interfaces Available in Java?

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What is Immutability in Java Functional Programming?

In this lesson, you will learn how immutability is achieved through functional programming.

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What are Pure & Impure Functions?

This lesson details pure and impure functions with various examples for understanding.

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What Problems Does Functional Programming Solve in Java?

Functional programming solves almost all of the business use cases OOP solves. In fact, functional programming reduces bugs due to its immutability in nature.

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How Functional Programming is Different From OOP?

In this lesson, you will learn about functional programming and the fundamental differences between object-oriented and functional programming.

Free Coursera Certificate: For Beginner And Advanced

With over 87 million students registered for upskilling, degrees, and master-track, Coursera is the most trusted learning platform for students.

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What is Java? Everything You Need To Know in 2023

LTS Version Release Date Extended support until Java SE 8 18th March 2014 December 2030 for Oracle, November 2026 for Red Hat Java SE 11 25th September 2018 September 2026 for Oracle, September 2026 for Azul, October 2024 for Red Hat Java SE 17 14th September 2021 September 2029 or

What is Java? Everything You Need To Know in 2023
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Getting Started With Streams API

Why are we even using Java Streams API? Isn't Java collections doing the job before Java SE8? You will learn about the importance of functional programming using streams API.

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What are Java Streams?

This is the introductory lesson on Java streams. You will learn why Java introduces streams and how developers can take advantage of them.