This is a Java Quiz

Question

1.     C and C++ are __________-threaded languages whereas Java is a __________-threaded language.

2.     Three reasons an alive thread might not be Runnable are that it is _________, _________, and ___________.

3.     A thread enters a Dead state when ___________.

4.     A thread’s priority ca be changed with method ___________.

5.     A thread may give up processor to a thread of the same priority by calling Thread method ____________.

6.     Ultimately, all data items processed by a computer are reduced to combinations of ________ and ________.

7.     A group of related files is called a ______________.

8.     RandomAccessFile method ________ reads an integer from the specified stream.

True or False:

9.     A thread is not Runnable if it is dead.

10. The programmer must explicitly create System.in, System.out and System.err.

11. Methods “seek” must seek relative to the beginning of a file.

Review:

1.     What are the four main parts of a class?

2.     How to you change a private variable within a class?

3.     What is the difference between private, protected and public access modifiers?

4.     What is the difference between a class and array?

5.     How do you declare an array in Java?

Answer 1

C and C++ are single-threaded languages whereas Java is a multi-threaded language.

Three reasons an alive thread might not be Runnable are that it is blocked, waiting, and sleeping.

A thread enters a Dead state when it completes its execution.

A thread’s priority can be changed with method setPriority().

A thread may give up the processor to a thread of the same priority by calling Thread method yield().

Ultimately, all data items processed by a computer are reduced to combinations of 0s and 1s.

A group of related files is called a database.

RandomAccessFile method readInt() reads an integer from the specified stream.

True or False:

9. True. A thread is not Runnable if it is dead.

False. System.in, System.out, and System.err are automatically created.

True. Methods "seek" must seek relative to the beginning of a file.

Review:

What are the four main parts of a class?

Attributes/Fields: These define the state of the object.

Methods/Functions: These define the behavior of the object.

Constructor: Special method used for initializing newly created objects.

Inner classes & interfaces (optional): Classes & interfaces defined within a class.

How do you change a private variable within a class?

Through setter methods or inside the class methods where it's accessible.

What is the difference between private, protected, and public access modifiers?

private: The member is accessible only within its own class.

protected: The member is accessible within its own package and by subclasses.

public: The member is accessible from any other class.

What is the difference between a class and an array?

Class: A blueprint for creating objects (a particular data structure), containing variables and methods to describe the object's behavior.

Array: A data structure that can hold more than one value at a time. It is a collection of variables that are accessed with an index.

How do you declare an array in Java?

dataType[] arrayName; or dataType arrayName[];

Example: int[] myArray; or int myArray[];

I hope this helps! If you have any other questions or need clarification on any points, let me know.

Answer 2

1.   Single , multi

2.   Waiting, Sleeping, Blocked for input/output

3.   Its run method terminates

4.   SetProirity

5.   Yield

6.   Ones, zeros

7.   Database

8.   ReadInt

9.   True

10.    False. These three streams are created automatically for the programmer

11.    True

Review answers:

1.   Name, variables, methods, constructor

2.   Through a method call

3.   Private – data is available within the class only,

Protected – data is available within class or subclass,

Public – data is available inside or outside of the class definition.

4.   Class is a container of various data type, Array can only contain one type of data.

5.   int array[] = { 1,3,2,5,6,7};