Java Developer OCA Questions Flashcards

It can be extended by another interface.

Tell me about the keyword implements.

Which logical operators are known as 'short circuiting logical operators'?

By default (i.e. no modifier) the member is only accessible to classes in the same package and subclasses of the class.

You cannot specify visibility of local variables.

Local variables always have default accessibility.

Local variables can be declared as private.

Local variables can only be declared as public.

A functional interface has exactly one method and it must be abstract.

A functional interface has exactly one method and it may or may not be abstract.

A functional interface must have exactly one abstract method and may have other default or static methods.

A functional interface must have exactly one static method and may have other default or abstract methods.

The 'default' constructor is provided by the compiler only if the class and any of its super classes does not define any constructor.

The 'default' constructor takes no arguments.

A default constructor is used to return a default value.

To define a default constructor, you must use the default keyword.

The 'default' constructor is always public.

Using a continue in a while loop causes the loop to break the current iteration and start the next iteration of the loop.

A character literal can be used as a value for a case label.

A 'long' cannot be used as a switch variable.

An empty switch block is a valid construct.

A switch block must have a default label.

If present, the default label must be the last of all the labels.

What is java.util.function.Predicate?

A method with no access modifier defined in a class can be overridden by a method marked protected in the subclass.

Using a break in a while loop causes the loop to break the current iteration and start the next iteration of the loop.

What class of objects can be declared by the throws clause?

Tell me something about scope.

Which class should you use to represent just a date without any timezone information?

A try statement must always have a ________ associated with it.

Does the String class have a reverse method?

Tell me something about fields in an interface.

What happens when you call System.exit(0) in a try block followed by a finally block?

What are the primitive data types?

What is the correct declaration for an abstract method 'add' that takes no arguments and returns nothing?

What does the zeroth element of the string array passed to the standard main method contain?

Which exception should a Java programmer throw explicitly?

Identify the valid members of Boolean class.

An abstract class can be extended by an abstract or a concrete class.

An abstract class cannot implement an interface.

A concrete class can be extended by an abstract or a concrete class.

An interface can be extended by another interface.

An interface can be extended by an abstract class.

The modulus operator % can only be used with integer operands.

The arithmetic operators *, / and % have the same level of precedence.

&& can have integer as well as boolean operands.

~ can have integer as well as boolean operands.

How many times can the keyword 'package' appear in a Java source file?

LocalDate, LocalTime, and LocalDateTime extend Date.

LocalDate, LocalTime, and LocalDateTime implement TemporalAccessor.

Both LocalDate and LocalTime extend LocalDateTime, which extends java.util.Date.

LocalDate, LocalTime, and LocalDateTime implement TemporalAccessor and extend java.util.Date.

What is the correct order of restrictiveness for access modifiers?

Are private members inherited?

What can be the type of a catch argument?

If a RuntimeException is not caught, the method will terminate and normal execution of the thread will resume.

An overriding method must declare that it throws the same exception classes as the method it overrides.

The main method of a program can declare that it throws checked exceptions.

A method declaring that it throws a certain exception class may throw instances of any subclass of that exception class.

Finally blocks are executed if and only if an exception gets thrown while inside the corresponding try block.

Tell me more about how exceptions are handled.

Is it possible to create arrays of length zero?

The 'default' constructor is provided by the compiler only if the class does not define any constructor.

The 'default' constructor initializes the instance members of the class.

The 'default' constructor calls the no-args constructor of the super class.

The 'default' constructor initializes instance as well as class fields of the class.

The 'default' constructor is provided by the compiler if the class does not define a 'no-args' constructor.

The private keyword can never be applied to a class.

The synchronized keyword can never be applied to a class.

The synchronized keyword may be applied to a non-primitive variable.

The final keyword can never be applied to a class.

A final variable can be hidden in a subclass.

Tell me about the final keyword.

How can you declare a method someMethod() such that an instance of the class is not needed to access it?

Is this a valid declaration in a class? abstract int absMethod(int param) throws Exception;

Is this a valid declaration in a class? abstract native int absMethod(int param) throws Exception;

Is this a valid declaration in a class? float native getVariance() throws Exception;

Is this a valid declaration in a class? abstract private int absMethod(int param) throws Exception;

Subclasses must define all the abstract methods that the superclass defines.

A class implementing an interface must define all the methods of that interface.

A class cannot override the superclass's constructor.

It is possible for two classes to be the superclass of each other.

An interface can implement multiple interfaces.

List three classes that can be thrown using a throw statement.

Private methods cannot be overridden in subclasses.

A subclass can override any method in a non-final superclass.

An overriding method can declare that it throws a wider spectrum of checked exceptions than the method it is overriding.

The parameter list of an overriding method must be a subset of the parameter list of the method that it is overriding.

The overriding method may opt not to declare any throws clause even if the original method has a throws clause.

The extends keyword is used to specify inheritance.

A subclass of a non-abstract class cannot be declared abstract.

A subclass of an abstract class can be declared abstract.

A subclass of a final class can be abstract.

A class, in which all the members are declared private, cannot be declared public.

An interface may extend an interface.

An interface may extend a class and may implement an interface.

A class can implement an interface and extend a class.

A class can extend an interface and can implement a class.

An interface can only be implemented and cannot be extended.