1Z0-811 1Z0-811 Java Operators and Control Flow 2

Question 1

What is the difference between `==` and `.equals()` when comparing String objects in Java?

Accepted Answer

`==` compares references; `.equals()` compares content

Answer

`==` compares object references (memory addresses), while `.equals()` on String compares the actual character content.

Question 2

Which loop is guaranteed to execute its body at least once?

Accepted Answer

do-while loop

Answer

The `do-while` loop evaluates its condition after executing the body, so it always runs at least once regardless of the condition.

Question 3

What is the correct syntax for a `switch` statement's default case in Java?

Accepted Answer

default: { }

Answer

The `default` keyword in a switch statement defines the block that executes when no other case matches.

Question 4

Which of the following correctly describes the `break` statement in a `switch` block?

Accepted Answer

It prevents fall-through to the next case

Answer

Without a `break` statement, execution falls through to the next case in a switch block; `break` prevents this by exiting the switch.

Question 5

What is the output of `int i = 0; while(i < 3) { System.out.print(i + " "); i++; }`?

Accepted Answer

0 1 2

Answer

The loop prints i (starting at 0) and increments it after each print, running while i < 3, so it outputs 0, 1, and 2.

(1Z0-811) Oracle Java SE11 Programmer Practice Test