Chapter 1

Question 1

what is an object oriented programming language

Answer 1

This is a language where code is defined in classes and those are instantiated into objects when called upon in runtime.

Question 2

what is the release interfall of new Java versions.

Answer 2

Every 6 months.

Question 3

List 5 benefits of Java

Answer 3

Object oriented, 
Encapsulation, 
Platform independent, 
Robust,
Simple,
Secure,
Multithreaded,
Backward Compatibility,

Question 4

What is a java class

Answer 4

A class is a repeatable buildingblock that can be used to build up your programs. A class contains all parts and characteristics of such a building block

Question 5

What is the difference between a object and a class

Answer 5

A object is a copy of a class used in runtime.

The (JVM) runtime enviroment uses a class to create a memory object.

Question 6

What are the two primary elements of a Java Class

Answer 6

Methods

Fields (also known as Variables)

Question 7

what does the {public} keyword do?

Answer 7

This is a “acces modifier” that declares the level of exposure to other parts of the java program. Public means any part of the program can use this method or class.

Question 8

what is the minimal syntax required to create a java class.

Answer 8

public/private class Car {
}
First the acces modifier keywords
Second the class keyword
Third is the name of the class
And the curly brackets contain the methods and variables

Question 9

What does the private keyword do?

Answer 9

This is a “acces modifier” that declares the level of exposure to other parts of the java program. Private means that this class or method can NOT be used by other parts of the java program.

Question 10

What is this : //

Answer 10

The begin of a comment in the code. A single line of text that is ignored during runtime.

Question 11

What is the correct syntax for a Multiline comment

Answer 11

/* (beginning)

• (lines, repeat until you have enough )
• / (end of comment)

Question 12

What is the difference between a multiline comment and Javadoc comment

Answer 12

it starts with /** instead of /* and it is read by the javadoc tool where other comments are ignored.

Question 13

What is the JDK

Answer 13

Java Developers Kit, everything you need to create and run a Java program.

Question 14

What is the JRE

Answer 14

The Java runtime enviroment is part of the JDK and is the subset of java tools that run a program.

Question 15

what is the correct filename for a Javafile that contains

public class zoo

Answer 15

zoo.java
a java file can only contain one public class and the name of the javefile has to match the name of this class.

Question 16

What is the main method

Answer 16

The main method tells the java enviroment where to begin working.

Question 17

Describe the static keyword

Answer 17

The static keyword binds a method to its class name. When other parts of the program call the class the static method is the entry point of this class.

Question 18

describe the void keyword

Answer 18

the void keyword is a return type for a method. This type declares that the method won’t return anything and returns control silently.

Question 19

When to use the void keyword

Answer 19

use this return type keyword if your method or class does not give a response.

Question 20

what is contained in a method signature between these symbols ()

Answer 20

This is the parameter list, A list of variables with the correct types and names. For example
(int month) a integer named month
(string brand) a string named brand
(string[] args) a array of strings or ‘arguments’

Question 21

What is the correct java command to run the Zoo.class inside the city package without args

Answer 21

java city.Zoo

Question 22

How do you pass a argument into a object if your value contains a space like - The Netherlands

Answer 22

Use quotes, : “The Netherlands” is a single string value for java arguments.

Question 23

How to run a class without compiling it ?

Answer 23

Use the full file name of the class. For example Zoo.java instead of just Zoo.

Question 24

In what situation can you run code without compiling it ?

Answer 24

This is only possible for a program that is “Single file source code”.

Question 25

What are the valid options to run a program using the java command while passing the classpath to the jre

Answer 25

• cp : java -cp Filestructure ClassName
• classpath : java -classpath Filestructure ClassName
• -class-path : java –class-path Filestructure ClassName

Question 26

What are the valid options to compile a program using the javac command while passing the classpath to the jdk

Answer 26

• cp : javac -cp Filestructure ClassName
• classpath : javac -classpath Filestructure ClassName
• -class-path : javac –class-path Filestructure ClassName

Question 27

what do the -c and –create options do when using the jar command

Answer 27

Creates a new JAR file

Question 28

what do the -v and –verbose options do when using the jar command

Answer 28

Prints details when working with JAR files

Question 29

what do the -f and –file options do when using the jar command

Answer 29

it passes the filename of the new JAR file to the jar command.

Question 30

what does the -C options do when using the jar command

Answer 30

It points to a directory that contains files to be used to create the JAR

Question 31

What is the correct order of the following elements of a java file.
A : Import statements
B : Field declarations
C : Package declaration
D : Method Declarionts
E : Class Declarations

Answer 31

1 = C : Package Declaration
2 = A : Import statements
3 = E : Class Declarations
4 = B : Field declrations
5 = D : Method Declarations

Question 32

for java 11 what is the minimum and maximum amount of public classes in a .java file?

Answer 32

Minimum = 0 
Maximum = 1

Question 33

Does java allow operator overloading

Answer 33

No

Question 34

Java code compiled on windows can run on linux

Answer 34

Yes

Question 35

Java has pointers to specific locations in memory

Answer 35

No, java points to objects.