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Control the execution of code with common logic structures 

Level 1 Application Scripting

Joy Horvath

Instructional Designer

Understand high-level programming concepts (such as inheritance, encapsulation, data abstraction, and polymorphism) and how they are implemented. 

Level 2 Programming theory

The purpose of this pre-assessment is to make sure that you don’t have any knowledge gaps before moving on with the Custom VR Development mission. 

If you pass the pre-assessment, you should have no problem completing the rest of this pathway.

If you don’t pass the pre-assessment, we’ll provide some resources in the question feedback for each specific knowledge area. Try to spend a good amount of time improving your skills in these areas, then return here and try again!

Select the appropriate common Unity methods to use, e.g., Awake, Start, Update, FixedUpdate, Collision, and Trigger Events, given a desired feature to code

Achieve a desired result by using Unity API methods, given Unity’s script documentation

Achieve a desired result with different parameters by using various method overloads

Distinguish a correct use of any given Unity API method from an incorrect use

Control or trigger the state of components, such as an Animator Controller, Light, AudioSource, or User Interface element by using appropriate methods

Construct an input listener, given a scenario where a specific type of input is required

Print a message consisting of concatenated strings and variable values to the console by using Unity's Debug.Log method

Compose scripts that utilize various APIs

Deduce the purpose and expected result of a given block of code

Accomplish a specific task by constructing a viable method declaration, given a list of keywords and syntax elements

Structure methods by using void and return

Demonstrate ability to implement a given feature in code by recommending data types and logic flow for a new method

Write code that integrates into an existing system

Enable easier readability and debugging by correctly organizing classes to include only singular purpose code

Add new functionality to non-editable classes by applying extension methods

Organize and prevent conflicts between scripts by using namespaces

Manage the communication of a GameObject’s status changes to other objects in the application by using Events 

Write efficient, organized, and comprehensible code by correctly implementing the principles of object-oriented programming

Explain how the pillars of OOP work together to create organized, efficient code

Define abstraction

Define inheritance

Define polymorphism

Define encapsulation

Analyze the principal pillars of object-oriented programming

Veronica Brown

Write code that utilizes the various Unity APIs

Simplify code and make it reusable by correctly implementing the principles of inheritance and polymorphism

Make code more secure and usable by correctly implementing the principles of abstraction and encapsulation, including the use of interfaces

Which of the following statements are true about virtual methods? 

Which of the following statements are true about virtual methods?   Select all correct answers.  

You can override virtual methods in a child class.

A virtual method is only implemented if it is overridden by a child class.

A virtual method declared in a child class can be accessed by its parent class. 

The virtual keyword is used for a method if you want it to be able to be overridden by a child class. 

It cannot be private, otherwise it would not be able to be overridden. 

Unlike abstract methods, virtual methods do not have to be overridden in child classes; it is just an option if you want. 

Virtual methods cannot be accessed by parent classes.

For more information on virtual methods and overrides, check out this tutorial.

Read the documentation from the Unity Scripting API about Random.Range and then read the code  below. 

float randomFloat = Random.Range(0f, 100f);
int randomInt = Random.Range(0, 100);

Which of the following are possible values for the randomFloat and randomInt variables?

Read the documentation from the Unity Scripting API about Random.Range and then read the code  below.   float randomFloat = Random.Range(0f, 100f);
int randomInt = Random.Range(0, 100);  Which of the following are possible values for the randomFloat and randomInt variables?  

If you read the documentation closely, you will see that when using float parameters, the range is inclusive of (includes) the maximum value. When using ints, on the other hand, the range is exclusive of (does not include) the maximum value. Therefore, the randomInt cannot actually be the maximum value of 100. The highest it could be would be 99. An int also must be a whole number, which means it could not be 50.5. 

If you want to brush up on reading Scripting API as well as Inclusive vs Exclusive rules, check out these resources:

Which of the following statements are true about parent (base) and child (derived) classes? 

Which of the following statements are true about parent (base) and child (derived) classes?   Select all correct answers.  

In a class declaration, a derived class can only define a single base class. 

Protected variables and methods can be accessed from any child class. 

Private variables and methods can be accessed from any child class.

If Class C derives from Class B, which derives from Class A, Class C only inherits behaviors from Class B.

Although a class can only define a single parent class, it inherits behaviors from any class that its parent class derives from, too. The “protected” access modifier is between public and private. Protected variables and methods can be accessed by any deriving class, but that’s it. 

For more information on inheritance, check out this tutorial on C# inheritance.

public class Enemy : MonoBehaviour {
   public static int EnemyHealth = 100;
}

What is the effect of using the static modifier here?

The code below uses the static modifier: public class Enemy : MonoBehaviour {
   public static int EnemyHealth = 100;
} What is the effect of using the static modifier here? Select all correct answers.  

Only a single copy of this variable can exist, which means that if you had multiple enemies, they could not have different EnemyHealth values.

It means that this variable cannot be modified from any other class. 

It allows you to access the EnemyHealth variable from another class using only Enemy.EnemyHealth. You do not need a reference to the class. 

It prevents the value of this variable from changing after the first time it is set.

When a variable is declared as static, a single copy of the variable is created. Since you know this is the only copy of this variable, it can be referenced easily from other classes using only the ClassName.VariableName. This is very useful for variables that need to be referenced in a lot of different classes like GameManagers, Score, or Player Health. Since only one copy of the variable can exist, it is not a good solution for a class that will be shared among many objects, like an EnemyHealth value that would be shared among many instances of enemies.

For more information on the static modifier, check out this tutorial.

You are trying to create a new method that takes a number and multiplies it by two. Which method would do that?

private float DoubleNumber() { 
  return number *= 2;
}

private float DoubleNumber(float number) { 
  return number *= 2;
}

private void DoubleNumber(float number) {
  return number *= 2;
}

private void DoubleNumber() {
  return number *= 2;
}

You are trying to create a new method that takes a number and multiplies it by two. Which method would do that?  Method 1 private float DoubleNumber() { 
  return number *= 2;
}  Method 2 private float DoubleNumber(float number) { 
  return number *= 2;
}  Method 3 private void DoubleNumber(float number) {
  return number *= 2;
}  Method 4 private void DoubleNumber() {
  return number *= 2;
}  

Since it needs to “return” a value, it should have a return type of “private float” as opposed to “private void.” Since it needs to take a number, it needs a float parameter (“float number”).

For more information on functions, check out this tutorial.

The following message was displayed in the console: “Monica has 20 dollars”.

string[] names = new string[] { "Steve", "Monica", "Eric" };
int money = 5;

void Start() {
  money *= 2;
  PrintNames();
}

void PrintNames () {
  Debug.Log("Monica has " + money/2 + " dollars"); // Line 1
  Debug.Log(names[1] + " has " + money*2 + " dollars"); // Line 2
  Debug.Log(names[2] + " has " + money*2 + " dollars"); // Line 3
  Debug.Log(names[Monica] + " has " + money/2 + " dollars"); // Line 4
}

Which of the line options in the PrintNames function produced it?

The following message was displayed in the console: “Monica has 20 dollars”.  string[] names = new string[] { "Steve", "Monica", "Eric" };
int money = 5;

void Start() {
  money *= 2;
  PrintNames();
}

void PrintNames () {
  Debug.Log("Monica has " + money/2 + " dollars"); // Line 1
  Debug.Log(names[1] + " has " + money*2 + " dollars"); // Line 2
  Debug.Log(names[2] + " has " + money*2 + " dollars"); // Line 3
  Debug.Log(names[Monica] + " has " + money/2 + " dollars"); // Line 4
}  Which of the line options in the PrintNames function produced it?  

Debug.Log(names[1] + " has " + money*2 + " dollars"); is correct.

Arrays start with index 0, so “Monica” has the index value of “1” (names[1]). In start, money is multiplied by 2, making it 10, so “money*2” would give you the value of 20.

For more information on Arrays, check out this video.

Which of the following statements about methods are correct? 

Which of the following statements about methods are correct?   Select all correct answers.  

If there was a Method declared as “private void RenameObject(string newName)”, you could call that method with “RenameObject(“Charlie”);”

Methods must be passed at least one parameter.

A method with an “int” return type could include the code “return true;”.

Methods with a “void” return type cannot be passed parameters.

A. Methods do not necessarily require parameters

B. Methods with a “void” return type can be passed parameters. “void” means that it just does not return anything.

C. A method with an “int” return type could not include the code, “return true;”, since true is a bool, not an int.

D. If there was a method declared as “private void RenameObject(string newName)”, you would have to pass it a string parameter. “Charlie” is a string parameter, so this would be valid.

The code below shows the manual implementation of a property in C#. 

private string _playerName;
public string PlayerName
{
   get { return _playerName; }
   set { _playerName = value; }
}

There is a more concise “auto-implemented” version of this code that accomplishes the same thing. What is it?

The code below shows the manual implementation of a property in C#.   private string _playerName;
public string PlayerName
{
   get { return _playerName; }
   set { _playerName = value; }
}  There is a more concise “auto-implemented” version of this code that accomplishes the same thing. What is it?  

public string PlayerName { get(); set(_playerName); }

private string PlayerName { get; private set; }

public string _playerName { get PlayerName; set _playerName; }

The format for an auto-implemented property is:

This allows other classes to get and set this value outside the class. Properties are used to achieve encapsulation in your code, which is one of the principles of object-oriented programming.

For more information on properties, check out this video.

Pre-assessment for VR Development

Scripting

ElizabethMidgley

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Pre-assessment for VR Development

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