Oracle 1z0-830 Dumps

In this code, we have two interfaces and a class with a main method:

WithDefaultMethod Interface:

Declares a default method print() that outputs "default".

WithStaticMethod Interface:

Extends WithDefaultMethod.

Declares a static method print() that outputs "static".

DefaultAndStaticMethods Class:

Contains the main method, which calls WithStaticMethod.print().

Key Points:

Static Methods in Interfaces:

Static methods in interfaces are not inherited by implementing or extending classes or interfaces. They belong solely to the interface in which they are declared.

Default Methods in Interfaces:

Default methods can be inherited by implementing classes, but they cannot be overridden by static methods in subinterfaces.

Execution Flow:

The main method calls WithStaticMethod.print().

This invokes the static method print() defined in the WithStaticMethod interface, which outputs "static".

Therefore, the program compiles successfully and prints static.

In this code, now is assigned the current date using LocalDate.now(). The goal is to format this date to the ISO week date format, which represents dates in the YYYY-'W'WW-E pattern, where:

YYYY: Week-based year

'W': Literal 'W' character

WW: Week number

E: Day of the week

Given that the present day is December 31, 2024, this date falls in the first week of the week-based year 2025. Therefore, the ISO week date representation would be 2025-W01-2, where '2' denotes Tuesday.

Among the provided formatters:

format1: This line attempts to create a DateTimeFormatter using a constructor, which is incorrect because DateTimeFormatter does not have a public constructor that accepts a pattern directly. This would result in a compilation error.

format2: This is correctly assigned the predefined DateTimeFormatter.ISO_WEEK_DATE, which formats dates in the ISO week date format.

format3: This line attempts to create a DateFormat instance using a field, which is incorrect because DateFormat does not have such a constructor. This would result in a compilation error.

format4: This line attempts to get a DateFormat instance using an integer field, which is incorrect because DateFormat.getDateInstance() does not accept such parameters. This would result in a compilation error.

Therefore, the only correct and applicable formatter is format2. Using format2 in the now.format() method will produce the desired output: 2025-W01-2.

In Java, a lambda expression can have two forms for its body:

Single Expression:A concise form where the body consists of a single expression. The result of this expression is implicitly returned.

Example:

java

(a, b) -> a + b

In this example, (a, b) are the parameters, and a + b is the single expression that adds them together.

Statement Block:A more detailed form where the body consists of a block of statements enclosed in braces {}. Within this block, you can have multiple statements, and if a return value is expected, you must explicitly use the return statement.

Example:

java

(a, b) -> {

int sum = a + b;

System.out.println("Sum is: " + sum);

return sum;

}

In this example, the lambda body is a statement block that performs multiple actions: it calculates the sum, prints it, and then returns the sum.

Given the options:

A. Two statements:While a lambda body can contain multiple statements, they must be enclosed within a statement block {}. Simply having two statements without braces is not valid syntax for a lambda expression.

B. An expression and a statement:Similar to option A, if a lambda body contains more than one element (be it expressions or statements), they need to be enclosed in a statement block.

C. A statement block:This is correct. A lambda expression can have a body that is a statement block, allowing multiple statements enclosed in braces.

D. None of the above:This is incorrect since option C is valid.

E. Two expressions:As with options A and B, multiple expressions must be enclosed in a statement block to form a valid lambda body.

Therefore, the correct answer is C: A statement block.