1Z0-811 Timed Practice Test 4 — 10 Questions

Question 1

Given the code: int[] arr = {1,2,3}; for(int x : arr) { if(x==2) continue; System.out.print(x); } What is the output?

Accepted Answer

13. The enhanced for loop iterates over the array {1,2,3}. When x equals 2, the continue statement skips the remainder of the loop body for that iteration, so System.out.print(x) is not executed for 2. Thus, only 1 and 3 are printed, producing output '13'.

Answer

2

Answer

Compilation error

Answer

123

Question 2

Which THREE statements are true about the break and continue statements in Java? (Choose three.)

Accepted Answer

A labeled break can be used to exit an outer loop.. Option A is correct because a labeled break in Java allows you to specify a label on an outer loop and then use 'break label;' to exit that outer loop directly, not just the innermost loop. This is useful for breaking out of nested loops when a condition is met in an inner loop.

Answer

The continue statement can be used to exit a loop entirely.

Answer

The break statement cannot be used outside a loop.

Question 3

Given: boolean a = false; boolean b = true; boolean c = true; System.out.println(a || b && c); What is the output?

Accepted Answer

true. In Java, the logical AND operator (&&) has higher precedence than the logical OR operator (||). Therefore, the expression `a || b && c` is evaluated as `a || (b && c)`. Given `a = false`, `b = true`, and `c = true`, `b && c` evaluates to `true`, and then `false || true` evaluates to `true`. Thus, the output is `true`, making option D correct.

Answer

false

Answer

Compilation fails

Answer

None of the above

Question 4

Given: String str = "Java"; str = str.concat(" SE"); str.replace('a', 'A'); System.out.println(str); What is the output?

Accepted Answer

Java SE. Option C is correct because the `concat` method returns a new String "Java SE" which is assigned back to `str`. The `replace` method also returns a new String but its result is not assigned to any variable, so the original `str` remains unchanged. The final `println` outputs the current value of `str`, which is "Java SE".

Answer

Java

Answer

JAVA SE

Answer

JAvA SE

Question 5

What is the output of: int i = 1; i = i++; System.out.println(i);

Accepted Answer

1. Option D is correct because in Java, the expression `i = i++` uses the post-increment operator, which first stores the current value of `i` (1) for the assignment, then increments `i` to 2, but the stored original value (1) is then assigned back to `i`. Thus, `i` remains 1, and the output is 1.

Answer

Compilation fails

Answer

0

Answer

2

Question 6

Which operator is used to compare two strings for value equality in Java?

Accepted Answer

equals(). Option D is correct because the equals() method in Java's String class compares the actual character sequences of two strings for value equality. Unlike the == operator, which checks reference equality (whether two references point to the same object in memory), equals() performs a lexicographic comparison of the string contents, returning true if and only if both strings have the same length and the same characters in the same order.

Answer

compareTo()

Answer

=

Answer

==

Question 7

A developer writes: String s = "Hello"; s.concat(" World"); System.out.println(s); What is the output?

Accepted Answer

Hello. Option C is correct because strings in Java are immutable. The `concat()` method returns a new string but does not modify the original string `s`. Since the return value is not assigned to any variable, the original string `s` remains unchanged, so `System.out.println(s)` prints "Hello".

Answer

Compilation fails

Answer

Hello World

Answer

Hello World

Question 8

What is the output of the code?

Accepted Answer

0 1 3 4. The code uses a for loop with an if condition that skips the iteration when the loop variable equals 2 using the continue statement. Therefore, the loop prints 0, 1, 3, and 4, but not 2. Option D correctly lists this output.

Answer

0 1 2 3 4

Answer

1 3 4

Answer

0 1 2 3

Question 9

Which THREE of the following expressions evaluate to true? (Assume int a=5, b=10)

Accepted Answer

a < b. Option B is correct because the expression 'a < b' compares the integer values of a (5) and b (10). Since 5 is less than 10, the relational operator '<' returns the boolean value true.

Answer

a == b

Answer

a >= b

Question 10

Which loop best suits a scenario where the number of iterations is unknown and depends on user input?

Accepted Answer

while loop. The while loop is best when the number of iterations is unknown and depends on user input because it evaluates a boolean condition before each iteration, allowing the loop to continue as long as the condition remains true. This is ideal for scenarios like reading user input until a sentinel value is entered, where the exact number of iterations cannot be predetermined.

Answer

for loop

Answer

for-each loop

Answer

do-while loop