docs(Lambda): summarize key benefits of Java Lambda Expressions

What
- Documented main advantages of using lambda expressions in Java.
- Highlights include:
  1. Concise and readable code replacing verbose anonymous inner classes.
  2. Reduced boilerplate by removing repeated syntax elements.
  3. Improved maintainability via shorter and clearer logic.
  4. Support for functional programming style and higher-order functions.
  5. Seamless integration with Collections and Streams API.
  6. Declarative programming style: focusing on "what" instead of "how".
  7. Built-in support for parallelism with parallel streams.
  8. Increased flexibility by treating functions as first-class citizens.

Why
- Provides developers with a clear reference on why lambdas are valuable in Java development.
- Reinforces the motivation for using lambdas beyond syntax sugar.
- Encourages adoption of functional/declarative paradigms for cleaner and more scalable code.
- Acts as a quick educational note or onboarding reference for teams new to lambdas.

How
- Organized explanation into numbered benefits with supporting details and examples.
- Provided quick recap section summarizing the key advantages.
- Connected lambdas to Streams API and parallelism to show practical usage.
- Kept language simple, focusing on developer experience and readability.

Logic
- Inputs: existing Java code practices (anonymous classes, loops, verbose patterns).
- Outputs: simplified, expressive code enabled by lambdas.
- Flow:
  1. Identify drawbacks of older Java styles (verbosity, boilerplate).
  2. Show how lambdas replace them with concise functional constructs.
  3. Demonstrate added flexibility and integration with Streams/Collections.
- Edge cases:
  - While lambdas improve readability, overuse in deeply nested chains may reduce clarity.
  - Debugging stack traces can sometimes be less explicit due to generated synthetic classes.
- Complexity / performance:
  - Lambdas compile into invokedynamic bytecode, avoiding anonymous class instantiation overhead.
  - Parallelism benefits depend on workload size; small collections may not benefit.
- Concurrency / thread-safety:
  - Stateless lambdas are naturally thread-safe.
  - Developers must ensure captured variables are effectively final.
- Error handling:
  - Checked exceptions cannot be thrown directly inside functional interfaces without wrappers.

Real-life applications
- Cleaner event handling in GUI frameworks.
- Compact comparators for sorting collections.
- Data processing pipelines with Streams (map/filter/reduce).
- Parallel computation on large datasets with minimal syntax.
- Business logic injection via functional interfaces without creating full classes.

Notes
- Prefer method references (e.g., String::toUpperCase) when lambdas would only call an existing method.
- Combine lambdas with @FunctionalInterface for custom functional types.
- Balance conciseness with readability; avoid overly complex inline lambdas.
- Lambdas align Java with modern functional features, making codebases more expressive and future-friendly.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Java 8 Crash Course/Lambda Expression/src/Benefits of Lambda Expressions.txt

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+🔹 Benefits of Lambda Expressions:
+	1.	Concise and Readable Code
+	•	Without lambdas, you usually need anonymous inner classes for functional interfaces.
+	•	Lambdas replace that with a few lines of compact code, making it cleaner and easier to read.
+
+	2.	Less Boilerplate
+	•	No need to repeat method names, access modifiers, or return types.
+	•	Just focus on what the function does, not on all the syntax overhead.
+
+	3.	Improved Maintainability
+	•	Shorter, clearer code is easier to debug and maintain.
+	•	Reduces clutter from anonymous classes.
+
+	4.	Functional Programming Style
+	•	Lambdas bring functional programming concepts into Java.
+	•	They let you pass behavior (functions) as arguments, enabling higher-order functions.
+
+	5.	Better with Collections API
+	•	Lambdas work seamlessly with the Streams API and Collections framework (introduced in Java 8).
+	•	Example: filtering, mapping, reducing collections becomes one-liner operations.
+
+	6.	Encourages Declarative Programming
+	•	Instead of describing how to do something (loops, iteration), you describe what you want.
+	•	Makes code closer to natural language.
+
+	7.	Supports Parallelism
+	•	When combined with parallel streams, lambdas allow simpler parallel processing of data,
+	    making multi-core utilization easier.
+
+	8.	Increased Flexibility
+	•	Functions can be stored in variables, passed as arguments, or returned from methods.
+	•	This was harder before lambdas.
+
+⸻
+
+Quick Recap:
+•	Cleaner and shorter code
+•	Reduces boilerplate
+•	Works great with Streams & Collections
+•	Supports functional and declarative style
+•	Easier parallelism