1Z0-811 Practice Test 8 — 10 Questions

Question 1

Given: byte b = 10; b = b + 1; Which statement is true?

Accepted Answer

Compilation error because byte cannot be assigned int.. In Java, the expression `b + 1` performs binary numeric promotion, widening the `byte` operand to `int` before addition. The result is an `int` (11), which cannot be implicitly assigned back to a `byte` variable without a cast. Therefore, `b = b + 1;` causes a compilation error: 'incompatible types: possible lossy conversion from int to byte'. Option C correctly identifies this error.

Answer

The value of b becomes 11.

Answer

b is automatically widened to int then assigned back without error.

Answer

The expression b+1 results in a byte.

Question 2

Which two of the following are primitives in Java? (Choose two.)

Accepted Answer

byte. A is correct because `byte` is a primitive data type in Java that stores 8-bit signed integers, ranging from -128 to 127. It is one of the eight primitive types defined in the Java language specification, not an object or reference type.

Answer

String

Answer

Integer

Answer

Boolean

Question 3

What is the output of the following? int x = Integer.MAX_VALUE; x++; System.out.println(x);

Accepted Answer

-2147483648. When x is Integer.MAX_VALUE (2147483647) and incremented, integer overflow occurs because Java int uses 32-bit two's complement representation. The value wraps around to the minimum int value, which is -2147483648, making D correct.

Answer

2147483647

Answer

0

Answer

Exception

Question 4

Which THREE are primitive data types in Java? (Choose three.)

Accepted Answer

double. `double` is one of the eight primitive data types in Java, used to represent double-precision 64-bit IEEE 754 floating-point numbers. Primitives are predefined by the language and stored directly in stack memory, not as objects.

Answer

Integer

Answer

String

Question 5

A developer writes a switch statement that checks the day of the week. The code uses fall-through to handle weekdays. What happens if a case does not end with a break?

Accepted Answer

Execution continues to the next case. In Java, when a case in a switch statement does not end with a break statement, execution falls through to the next case, continuing until a break is encountered or the switch block ends. This is known as fall-through behavior, which the developer intentionally uses to handle weekdays collectively.

Answer

The default case is executed

Answer

Compilation error

Answer

Runtime exception is thrown

Question 6

Which TWO access modifiers allow access from a subclass in a different package?

Accepted Answer

protected. (protected) is correct because the protected access modifier allows access to members of a superclass by subclasses in different packages, provided the subclass inherits from the superclass. Option E (public) is also correct because public members are accessible from any class, regardless of package or inheritance.

Answer

private

Answer

static

Answer

default (no modifier)

Question 7

A method is declared as: public static void main(String[] args) { }. Which statement is true?

Accepted Answer

The method can be called without creating an instance of the class.. The `static` modifier in the method signature means the method belongs to the class itself, not to any instance. Therefore, it can be invoked using the class name (e.g., `ClassName.main(args)`) without creating an object of the class. This is a fundamental characteristic of static methods in Java.

Answer

The method can be overridden in a subclass.

Answer

The method can return an int.

Answer

The method can be private.

Question 8

Which primitive type has a default value of 0.0f?

Accepted Answer

float. In Java, the default value for a float primitive is 0.0f. This is because float is a 32-bit IEEE 754 floating-point type, and its default initialization is 0.0f (with the 'f' suffix to denote a float literal). Option A is correct because it directly matches this specification.

Answer

long

Answer

double

Answer

int

Question 9

Which TWO of the following are primitive data types in Java?

Accepted Answer

double. (double) is correct because double is a 64-bit IEEE 754 floating-point primitive data type in Java, used for decimal values with double precision. Option D (int) is correct because int is a 32-bit signed two's complement integer primitive, the default integer type in Java. Both are part of the eight primitive types defined in the Java Language Specification.

Answer

String

Answer

Integer

Answer

Boolean

Question 10

Which THREE of the following statements about operators in Java are true?

Accepted Answer

The instanceof operator can be used to check if an object is an instance of a class.. The `instanceof` operator in Java is a binary operator used to test whether an object is an instance of a specific class, subclass, or interface. It returns `true` if the object is an instance of the specified type, otherwise `false`, and is commonly used for type checking before casting.

Answer

The right shift operator (>>) always fills with zeros.

Answer

The equality operator (==) compares the content of objects.