1Z0-811 Practice Test 4 — 10 Questions

Question 1

A class has a method that is marked as protected. Which statement is true about its accessibility?

Accepted Answer

Within the same package and subclasses. In Java, the protected access modifier allows access within the same package and by subclasses (even if they are in different packages). Option E correctly states this combination, which is the precise definition of protected access as specified in the Java Language Specification (JLS §6.6.2).

Answer

Only in subclasses

Answer

Only within the same package

Answer

Everywhere

Answer

Only within the same class

Question 2

Given: abstract class Shape { abstract void draw(); } class Circle extends Shape { void draw() {} } Which is true?

Accepted Answer

Circle must override draw(). Circle is a concrete class that extends the abstract class Shape, which declares the abstract method draw(). A concrete subclass of an abstract class must provide an implementation for all inherited abstract methods, unless the subclass is also declared abstract. Circle provides an implementation of draw() with an empty body, which satisfies the override requirement.

Answer

Shape cannot have a constructor

Answer

Shape s = new Shape(); is valid

Answer

draw() must be public in Circle

Question 3

What is the value of the expression (10 > 5) && (3 < 2)?

Accepted Answer

false. The expression (10 > 5) evaluates to true, and (3 < 2) evaluates to false. The logical AND operator (&&) returns true only if both operands are true. Since one operand is false, the entire expression evaluates to false. In Java, the result of a boolean expression is a boolean literal, not an integer.

Answer

1

Answer

true

Answer

0

Question 4

Which three of the following are valid ways to declare and initialize a variable of type int? (Choose three.)

Accepted Answer

int b = 0xA;. `0xA` is a hexadecimal integer literal in Java, representing the decimal value 10. Java allows hexadecimal literals using the prefix `0x` or `0X`, and they are valid for initializing an `int` variable.

Answer

int e = 10.0;

Answer

int c = 0b2;

Question 5

Which two statements about the Arrays class are true? (Choose two.)

Accepted Answer

The Arrays class provides a method to fill an array with a specific value.. The `Arrays.fill()` method allows you to assign a specific value to every element of an array, or to a specified range within the array. This is a static utility method provided by the `java.util.Arrays` class, and it works for both primitive and object arrays.

Answer

The Arrays class provides a method to sort only arrays of primitive types.

Answer

The Arrays class provides a method to perform binary search on any array.

Answer

The Arrays class provides a method to deep copy an array.

Question 6

A method is expected to receive an integer and return its square. Which method signature is correct?

Accepted Answer

int square(int x) { return x*x; }. The method signature specifies a return type of 'int' and includes the 'return' keyword to return the squared value. In Java, a method that returns a value must declare the return type before the method name and must use the 'return' statement to send the result back to the caller.

Answer

void square(int x) { return x*x; }

Answer

public square(int x) { return x*x; }

Answer

int square(int x) { x*x; }

Question 7

Refer to the exhibit.

What is the likely cause?

Accepted Answer

The variable 'value' is not declared. The error message indicates that the variable 'value' has not been declared before use. In Java, every variable must be declared with a type and name before it can be referenced. The compiler cannot find a declaration for 'value' in the current scope, so it reports a 'cannot find symbol' error, which is the typical symptom of an undeclared variable.

Answer

The package is missing

Answer

The class name is misspelled

Answer

The variable 'value' is out of scope

Answer

The variable 'value' is declared but not initialized

Question 8

A developer writes: int x; System.out.println(x); What is the result?

Accepted Answer

Compilation fails. B is correct because in Java, a local variable (such as `int x;` declared inside a method) must be initialized before it is used. The code attempts to print `x` without assigning a value, which violates the definite assignment rule and causes a compilation error.

Answer

null

Answer

Runtime error

Answer

0

Question 9

Given: int day = 3; switch(day) { case 1: System.out.print("A"); case 2: System.out.print("B"); case 3: System.out.print("C"); case 4: System.out.print("D"); } What prints?

Accepted Answer

"CD". The switch statement does not have break statements, so after matching case 3, execution falls through to case 4, printing 'C' then 'D'. The output is 'CD'.

Answer

"BCD"

Answer

"C"

Answer

"ABCD"

Question 10

Which two expressions evaluate to true? (Choose two)

Accepted Answer

10 > 5. The expression `10 > 5` uses the greater-than operator, which evaluates to `true` since 10 is indeed greater than 5. Option D is correct because `!false` evaluates to `true`, and the logical OR operator (`||`) returns `true` if at least one operand is `true`, so `false || true` yields `true`.

Answer

true && false

Answer

'a' == 'b'

Answer

3 < 3