[NEW] Oracle Certified Professional Java SE 11 Developer

Detailed Exam Domain CoverageCore Java Language Features (25%)Topics: Primitive data types, literals, and operators; Control flow statements and exception handling; Classes, interfaces, enums, and records; Java SE 11 language enhancements and preview features.Object-Oriented Programming and Design (25%)Topics: Encapsulation, inheritance, and polymorphism; Design principles (SOLID) and common design patterns; Access modifiers, inner classes, and nesting; Composition vs. inheritance decisions.Functional Programming and Streams (25%)Topics: Lambda expressions and method references; Functional interfaces and default methods; Stream pipeline operations (filter, map, reduce, collect); Optional API and handling nulls.Concurrency, JVM Internals, and Performance (25%)Topics: Thread lifecycle, Runnable, Callable, and executors; Synchronization, locks, and concurrent collections; Garbage collection algorithms and tuning; Class loading, module system, and JVM options.Earning your Oracle Certified Professional (OCP) Java SE 11 Developer credential is one of the most definitive ways to prove your backend engineering expertise. However, passing this exam requires more than just a general understanding of syntax. The actual exam is notorious for testing obscure edge cases, unexpected compiler behavior, and intricate API details that developers rarely think about during daily coding.I designed this practice test question bank to bridge the gap between knowing Java and passing the OCP exam. Instead of giving you simple definitions, these questions mirror the actual test environment's complexity. You will learn to spot the subtle traps built into questions about local variable type inference, stream execution order, and multi-threaded race conditions. Every question in this set includes a comprehensive breakdown, ensuring you understand exactly why the correct choice stands and why the other options fail.Practice Questions PreviewQuestion 1: Core Java Language FeaturesWhat is the result of attempting to compile and run the following code snippet?Javapublic class LambdaVar {    public static void main(String[] args) {        java.util.function.BinaryOperator bo = (var s1, String s2) -> s1 + s2; // Line 1        var dynamicList = new java.util.ArrayList<>(); // Line 2        dynamicList.add(10);        var item = dynamicList.get(0); // Line 3        System.out.println(item.getClass().getName());    }}A) Compiles fine and prints java.lang.Integer.B) Line 1 causes a compilation error because var cannot be mixed with explicit types in lambda parameters.C) Line 2 causes a compilation error because the diamond operator cannot be used with var without an explicit type context.D) Line 3 causes a compilation error because dynamicList defaults to an ArrayList of Object types and cannot resolve getClass().E) Line 1 and Line 2 both cause compilation errors.F) The code compiles successfully but throws a ClassCastException at runtime.Answers & Explanations:Correct Answer: BOption Breakdown:Why B is correct: Java 11 allows the use of var in lambda parameters, but it enforces a strict consistency rule. You must either use var for all parameters, use explicit types for all parameters, or use implicit types for all parameters. Mixing (var s1, String s2) is illegal and triggers a compilation error.Why A is incorrect: The code will never run to print anything because Line 1 breaks compilation rules.Why C is incorrect: Line 2 is perfectly valid. When var is combined with the empty diamond operator <>, Java infers the type as an ArrayList of Object.Why D is incorrect: Line 3 compiles without issue. Since dynamicList is an ArrayList