Prepare for the Java basics quiz

Review

A boolean represents a true or false value. A for-each loop visits the elements of an array or iterable.

Try the quiz

Open the interactive Java basics quiz. Your results stay in this browser.

Common Mistakes

Check empty inputs and invalid values before applying this operation to application data. State whether a method edits shared state or returns a separate value.

Review decisions rather than memorize output strings

For a value question, identify primitive versus reference representation, evaluation order, conversion and the exact operation. For an object question, draw which references share the same mutable state. For a collection question, name the implementation as well as the interface.

For a concurrency question, separate admission, visibility, atomic transition and completion. A volatile read, successful submit or cancelled future does not answer every one of those questions. Read the failure and shutdown clauses before choosing an option.

The Java quiz hub groups foundation, object, collection, generic, stream, thread, I/O and algorithm checks. Each result is a local self-check. Review its explanation and return to the linked lesson before retrying; a correct multiple-choice answer alone does not verify that a complete program meets the same contract.

Connect the contracts

Before choosing an answer, identify the value using types and numeric ranges.

Continue with the specific contracts in the Java quiz banks.