Day 1

Question 1

What’s an assembly language?

Answer 1

• A language created to make programming easier.
• Keywords like add, sub, result.

Question 2

How can you execute an assembly code?

Answer 2

Using an assembler

Question 3

Which languages are machine dependent?

Answer 3

Machine language
Assembly language
However, high-level languages are machine independent

Question 4

What’s a source code?

Answer 4

It’s a program written using a high-level programming language

Question 5

How is an interpreter different from a compiler?

Answer 5

An interpreter translates and executes the code line by line every time you run the program, so it gives an immediate feedback on errors

On the other hand, a compiler doesn’t do that, it translates the whole code all at once into a machine code executable file, so reporting of any error will be after the compilation

Question 6

What’s the term for a predefined Java code that can be used to develop programs?

Answer 6

API
Application Programming Interface

Question 7

What’s the term for a predefined Java code that can be used to develop programs?

Answer 7

API
Application Programming Interface

Question 8

Enumerate Java editions

Answer 8

• Java Standard Edition (SE)
• Java Enterprise Edition (EE)
• Java Micro Edition (ME)

Question 9

Enumerate Java editions

Answer 9

• Java Standard Edition (SE)
• Java Enterprise Edition (EE)
• Java Micro Edition (ME)

Question 10

What are these environments:
Eclipse, IntelliJ IDEA & NetBean?

Answer 10

They’re examples of Integrated Development Environment (IDE)

Question 11

What’s JDE?

Answer 11

JDE (** Java Development Environment**)
= Java Development Kit (JDK) + Java Virtual Machine (JVM)

Question 12

Which one doesn’t contain a code editor: JDE or IDE?

Answer 12

JDE
It includes all the essential tools to compile and run Java programs, but doesn’t include a code editor for writing and editing code

However an IDE contains a code editor and all the essential Java tools in addition to debugging tools

Question 13

Which environment gives Java the advantage to be machine independent?

Answer 13

Java Virtual Machine
which executes Java bytecode in the machine according to its requirements

Question 14

What’s the difference between these two lines?
1. return String method draw() {
code block
}
2. draw (“tree”);

Answer 14

1. It’s method declaration
2. This is method calling

Question 15

True of false?
We can NOT have a Java program without a main method

Answer 15

True

Question 16

Which convention is used to name a class?

Answer 16

Pascal Case Convention

Question 17

Write a complex variable name its correct convention

Answer 17

• The right convention is Camel Case
• Example: drawAPlane/ bendTheKnee

Question 18

public class Main {
code block
}

This program won’t work, give the reason

Answer 18

Because there’s no main method, so the correct code must be like this:
public class main {

   public static void                                                                  
   main(String[] args)  {
  
   }

}

Question 19

What’s the out in System.out.print() method?

Answer 19

out is an object (field) of a class (which is System)

Question 20

What’s the difference betweenprintln & print methods?

Answer 20

println displays parameters with lines breaking between them on the console window

print displays parameters all in one line one after another

Question 21

True or false?
The naming of a java file mustn’t necessarily be the same name of the class

Answer 21

False
It’s a must that the saved java file is named after the name of the class

Question 22

Using cmd to compile a java source code stored in desktop, what to type in cmd to guide it to desktop?

Answer 22

cd Desktop

Question 23

Using cmd to compile a java source code stored in desktop, what to type in cmd to guide it to desktop?

Answer 23

cd Desktop

Question 24

One of the following files extensions is the right one for JVM to run:
File.java
File.class

Answer 24

File.class
It’s the compiled file (bytecode) that can be used by JVM to be executed in any type of machine

Question 25

One of the following files extensions is the right one for JVM to run: File.java File.class

Answer 25

**File.class** It's the compiled file (*bytecode*) that can be used by JVM to be executed in any type of machine

Question 26

What does this line in cmd mean? C:\Users\Adel\Documents>javac Results.java

Answer 26

We order java compiler (*javac*) to compile a java file called **Results** which exists in Documents *Note* how the file java names always start with a capital letter; it's because it must take the naming of the file class and the naming of classes follow **Pascal Case Convention**

Question 27

In a standard newly-made java program, there's an option to run the program starting from **'Main.main()'**. What does this quotated sentence mean?

Answer 27

It means that the class **Main** has a method called **main** which was accessed using the dot operator**.** So running the program will execute what the method main entails

Question 28

Mention another use for the **comments** function besides writing notes? Note: we mean by comments function the use of '//' and '/* */'

Answer 28

Comments can also be used to eliminate a code so that the compiler ignores it (or part of it) when this code is suspected to cause an error. So if after the elimination the program runs smoothly that means the suspected code was incorrect

Question 29

What to use in order to make the compiler ignore a **multi-line text**?

Answer 29

We use a comment specifically this one: /* the comment that we wish to be ignored by the compiler */

Question 30

How to write the main method quickly in a new class?

Answer 30

Write **psvm* public static void main

Question 31

What's the quick way to write a method that prints out a string?

Answer 31

Write **sout** which prints a string to System.out

Question 32

Read this code: "public class Main { public static void main(String[] args) { } public static void giveGreeting() { System.out.println("Hello World"); } }" When trying to run this code, nothing displayed on the console. Why?

Answer 32

Because the 'sayGreatings' method was written **outside** the 'main' method *which is the starting point of execution*. When this starting point is empty, the compiler won't find a code to execute and thus nothing appears on the console

Question 33

You used this combo of keyboard buttons on a line of code: shift+alt+down arrow What's the expected change?

Answer 33

This code line will *move under* the next line in order

Question 34

Is it preferable to name a method **descriptively**?

Answer 34

Yes. A descriptive naming of a method makes it easier to know what the method will probably entail

Question 35

You want to call a method called 'tryRing' (created on Class1) on Class2, what will you write?

Answer 35

In the tab of Class2, I'll write: Class1.tryHelp() Explanation: write the class name then the dot operation and choose the method that was created in that class

Question 36

What's an "**Access Modifier**"?

Answer 36

It's a *keyword* that determines the **level of accessibility or visibility** a class, method or variables has in relation to other parts of the program

Question 37

Is '**static**' an access or non-access modifier, and explain further

Answer 37

static is a non-access modifier Our ability to access an object (or field) or methods using its name is due to this keyword '**static**'

Question 38

If we want to confine a method only to its class, what keyword to ise in its declaration?

Answer 38

'**Private**' keyword It ensures that the access level is only inside the class

Question 39

In a java program, this code was written: public String chooseColour(String colour) { return colour public static void main (String [] ergs) { System.out.print("Your choice " + chooseColour (purple) + "indicates something about your personality" } Did the method take an input from the user? What is the type of its return?

Answer 39

• No, it didn't take input from the user. Inputs are taken via a *Scanner* object. However, the value was assigned to the parameter (the variable which is **name**) when the method was called and given a value of "purple". • Type of return is: String. The return type is the same as the value type.

Question 40

What is meant by 'Command line arguments'?

Answer 40

They are the data (Strings) given to the main method which can be used accordingly

Question 41

How to write the main method in an **organized** fashion in its line? What's this process called

Answer 41

• We should leave a tab (= 4 spaces) at the beginning of the line • It's called*indentation*

Question 42

What's*'End-of-line'* code block style? Mention another style that can be used. Which one of those is used in java API source code?

Answer 42

• It's a style of putting the curly braces ,between which the code is blocked, **at the end of the same line** that starts the code block • Another style is: next-line style • End-of-line style is used in java API

Question 43

What shortcut in keyboard can you use to get to the begining of line?

Answer 43

"**home**" button

Question 44

How to move the cursor word by word using keyboard?

Answer 44

Using: Cntrl + Right or left arrows in the keyboard

Question 45

How to get to the begining of the file using shortcuts in the keyboard?

Answer 45

Press **pg up**

Question 46

In order to select a code block using keyboard shortcuts, which of the following is correct? A) shift + up or down arrows B) shift + alt + up or down arrows C) ctrl + W

Answer 46

C) ctrl + W For each press on these two, a bigger block is selected

Question 47

What's the function of the **"tab"** button on the keyboard?

Answer 47

It can be used as a shortcut for indentation. Typically when pressed, it'll leave 4 spaces and for each press it'll move another 4 spaces (another ident).

Question 48

If you put an ident using tab button but wish to quit that ident and go back ident by ident, what will you do?

Answer 48

I will use this shortcut: *shift + tab*

Question 49

How to duplicate a statement using keyboard shortcuts?

Answer 49

When the cursor is anywhere on the line, press "*ctrl + D*"

Question 50

You used *ctrl + /* on a line, what is the expected outcome?

Answer 50

That line will be a comment And to remove the commenting, we use the same shortcut again.