1z0-830 Free Practice Test

Given: java
Object myVar = 0;
String print = switch (myVar) { case int i -> "integer";
case long l -> "long"; case String s -> "string"; default -> "";
};
System.out.println(print); What is printed?

1. A. integer
2. B. long
3. C. string
4. D. nothing
5. E. It throws an exception at runtime.
6. F. Compilation fails.

Correct Answer: F

Given: java
public class SpecialAddition extends Addition implements Special { public static void main(String[] args) {
System.out.println(new SpecialAddition().add());
}
int add() {
return --foo + bar--;
}
}
class Addition { int foo = 1;
}
interface Special { int bar = 1;
}
What is printed?

1. A. 1
2. B. 2
3. C. It throws an exception at runtime.
4. D. Compilation fails.

Correct Answer: E

Given: java
interface A {
default void ma() {
}
}
interface B extends A { static void mb() {
}
}
interface C extends B { void ma();
void mc();
}
interface D extends C { void md();
}
interface E extends D { default void ma() {
}
default void mb() {
}
default void mc() {
}
}
Which interface can be the target of a lambda expression?

1. A. None of the above
2. B. C
3. C. A
4. D. E
5. E. B
6. F. D

Correct Answer: A

Which of the following methods of java.util.function.Predicate aredefault methods?

1. A. and(Predicate<? super T> other)
2. B. isEqual(Object targetRef)
3. C. negate()
4. D. not(Predicate<? super T> target)
5. E. or(Predicate<? super T> other)
6. F. test(T t)

Correct Answer: ACE

Given:
java
interface SmartPhone { boolean ring();
}
class Iphone15 implements SmartPhone { boolean isRinging;
boolean ring() { isRinging = !isRinging; return isRinging;
}
}
Choose the right statement.

1. A. Iphone15 class does not compile
2. B. Everything compiles
3. C. SmartPhone interface does not compile
4. D. An exception is thrown at running Iphone15.ring();

Correct Answer: A