D286 Java Fundamentals - Set 3 - Part 3

Correct Answer: Running setup code once when the class is first loaded

A static block executes once when the class is loaded into memory, used for one-time initialization of static fields requiring more than a simple assignment.

Correct Answer: The method returns no value

A void method performs its work without returning a value to the caller, though it may still use a bare return statement to exit early.

Correct Answer: An object whose state cannot change after construction

An immutable object's state is fixed at construction. String is the canonical example. Immutability makes objects inherently thread-safe and easier to reason about.

Correct Answer: Declaring fields private and final with no setter methods

Immutability requires private final fields, no mutating methods, and defensive copying of any mutable objects passed in or returned.

Correct Answer: true

The int 5 is promoted to the double 5.0 for the comparison, so the values are equal and the expression evaluates to true.

Correct Answer: A result exceeding the maximum value the type can represent, wrapping around

When arithmetic produces a value beyond the type's range, it silently wraps around to the opposite extreme rather than raising an error, causing subtle bugs.

Correct Answer: long

A long is a 64-bit signed integer, accommodating values far beyond the 32-bit range of int.

Correct Answer: A single 16-bit Unicode character

A char holds one 16-bit Unicode character. Character literals use single quotes, while String literals use double quotes.

Correct Answer: 'A' is a char literal and "A" is a String object

Single quotes denote a primitive char, while double quotes denote a String object. They are different types and behave differently.

Correct Answer: Easier to understand, test, reuse, and debug

Small focused methods are easier to name, reason about, test in isolation, and reuse, which substantially reduces defects and maintenance effort.