Greenfoot Ch 1- 4

Methods that are void methods are like commands Example: public void move()

• True

• False

Void means the method does not return anything.

• True

• False

1. Suppose the method to call is defined in the same class or inherited from another class

In general, the format is: methodName(parameters…)

• True

• False

Which is the best example of how to use braces when creating a conditional statement?

• If (condition) { statement(s); }

• If (condition) statement(s);

Common characteristics of a constructor’s signature.  It is the same name as the class It has no return type It is preceded by the public visibility modifier

• True

• False

A protected modier on a method means that the method

• may not be accessed directly by any code outside the class (can’t get to it with the ‘.’)
• is inherited by subclasses

• True

• False

To debug your code, the following methods are the best to use.

• Use the debugger and set breakpoints

• Use "System.out.println" to output information you would like to check

• Randomly guess and fix it by trial and error

Methods that return a value are like questions. Example: public boolean canMove()

• True

• False

 We know which format to use when declaring a methodName by checking for the static keyword.

• True

• False

1. Suppose the method is not in the same class or inherited from another class

In general, the format is:

• ClassName.methodName(parameters…) OR
• objectName.methodName(parameters…)

• True

• False

1. Why should you use Comments tags?   Two primary reasons

• To explain code you are writing

• To check for errors

• It makes your code prettier

Greenfoot.getRandomNumber(8) + 1; Thid method would return numbers between ____ and 8

“Functions” are represented by Java methods whose returnType is not void.

• True

• False

The terminal window appears automatically when the first System.out.println statement is executed.

• True

• False

Translate source code into machine code that a computer can understand and execute.

SetLocation(100, 150); The parameters of 100 and 150 tell you that  the y coordinate is 100 and the x coordinate is 150.

• True

• False

Mark all answers that are correct Write a method to show 50-50 probability

• GetRandomNumber(2) < 1

• GetRandomNumber(100) < 50

• GetRandomNumber(50) < 50

Complete this for loop that would create 5 different Worms automatically and place them in random locations in the world.                for ( int i = 0 ;  i < _______ ;  i++)       { addObject(new Worm(), Greenfoot.getRandomNumber(getWidth()), Greenfoot.getRandomNumber(getHeight());         }

Greenfoot.getRandomNumber(10); This method  would return numbers from 0 to ____

You do not have to use dot notation is a method is in the same class you are writing the method in.

• True

• False

A  __________________is a  mechanism used to pass additional data into a method. Example: public void move(distance);

Comments that describe your code are often concise and begin with action words. Assume the reader of your code already understands the language.

• True

• False

What is the method name for the following method? public void eat()

A class called Ant extends the Actor class.

• Ant is a super class to Actor

• Actor is the super class to Ant

• Actor is not a class

Write a statement that will declare an integer instance variable called count and set its initial value to 0. (2 marks)

• Public count = 0;

• Public int count = 0;

• Public void count = 0;

• Public void count();

Constructors can never have parameters.

• True

• False

This kind of error will allow your program to compile but will give you information that is wrong.

Write an if statement that would  play a sound when the “D” key or the “F” key is pressed, AND wormsEaten is between 3 and 6 inclusive. if (Greenfoot.isKeyDown(“D”) || Greenfoot.isKeyDown(“F”)  &&( wormEaten >= 3) && (wormsEaten <=6)))

• If (Greenfoot.isKeyDown(“D”) || Greenfoot.isKeyDown(“F”) &&( wormEaten >= 3) && (wormsEaten

• If (Greenfoot.isKeyDown(“D”) && Greenfoot.isKeyDown(“F”) ||( wormEaten >= 3) || (wormsEaten

If a class has subclasses, it is considered to be a _____________ class.

You do not have to use dot notation if a method is inherited.

• True

• False

Constructors do not have the same name as the class.

• False

• True

On the following picture "void setDirection(int direction)" is called  the  ____________________  of the method.

• Object

• Method

• Instance

• Signature

What kind of error will keep your program from compiling?  For example, you forget to put a ";" at the end of a variable that you declare.

Memory that belongs to the object that is used to store information(objects or values) for later use is called an ______________ variable. 

/* */ These tags are for single line code comments

• True

• False

Translate source code into byte code which the Java Interpreter (JVM – Java Virtual Machine) can understand.

Strings should be put in single quotes

• True

• False

1. You want the dimensions of the world in your Greenfoot scenario to be 200 cells by 300 cells and each cell will be 5 by 5 pixels. Complete the statement below to accomplish this: (3 marks)

  super(  ___  ,  ___  ,  ___ );

What is the return value of the following method: private boolean atWorldEdge()

Use an ________________  variable when it exhibits a natural “has-a” relationship to the object

What word is used to show that a class inherits methods and properties from a super class.

The method "static int getRandomNumber(int limit)"   is from which class?

Special methods that allow one to instantiate (construct) an object from a class.

To straighten out your code and make it have proper indentations, you can use __________ from the Edit Menu.

= is used as a Boolean statement to determine if something is true or false == assigns a value to the variable on the left side of the equals sign.

• True

• False

Attempt to always use( local or instance )  variables except when the variable exhibits a natural “has-a” relationship to the object. A student has a first name, last name, id, social security number   A car has a make, model, type, color

Write the method call for the method signature. (How would you call the method in your code?) public void eat( )

If (atWorldEdge()); This is the correct way to write the if conditional.

• True

• False