GCSE Unit 2 Prep - Greenfoot

How would you set the size of the Greenfoot world?

• super(9, 9, 100);

• world(9, 9, 100);

• world(9, 9);

• superWorld(9, 9, 100);

Answer explanation

This sets a world with a grid of 9 by 9 cells, where each cell contains 100 by 100 pixels.

In Greenfoot Java, which method is used to move an object within the world?

• setLocation()

• move()

• shift()

• transport()

Answer explanation

In Greenfoot Java, the move() method is used to move an object within the world. This method is typically called on an actor object to change its position by a specified amount. When move() is invoked, the object will be displaced by the specified distance in the direction it is currently facing. For example, if you have a character in a game and you want it to move forward, you can call the move() method to make it shift its position in the forward direction. e.g.

move(1) would move the object 1 space.

In Greenfoot Java, which method is used to change the direction an object is facing within the world?

• rotate()

• turn()

• spin()

• shift()

Answer explanation

In Greenfoot Java, the turn() method is used to change the direction an object is facing within the world. This method is typically called on an actor object to rotate it by a specified angle. When turn() is invoked, the object will rotate clockwise by the specified angle. For example, if you want a character in a game to turn right, you can call the turn() method with a positive angle to make it rotate in that direction.

e.g turn(90) will turn 90 degrees clockwise.

In Greenfoot Java, which method is used to generate a random number within a specified range?

• random()

• getRandomNumber()

• nextInt()

• generateRandom()

Answer explanation

n Greenfoot Java, the getRandomNumber() method is used to generate a random number within a specified range. This method takes an integer argument that represents the upper bound of the range (exclusive). The returned random number will be greater than or equal to zero and less than the specified upper bound. For example, if you call getRandomNumber(10), you will get a random number between 0 and 9 (inclusive).

Is this the correct way to implement a random number for move?

move(Greenfoot.getRandomNumber(2));

• Yes

• No

• Yes

• No

Answer explanation

This can also be used for turning a random amount:

turn(Greenfoot.getRandomNumber(360));

In Greenfoot Java, which method is used to check if a specific key is currently being pressed?

• Greenfoot.isKeyPressed("up")

• Greenfoot.isKeyDown("up")

• Greenfoot.isKeyHeld("up")

• Greenfoot.isKeyReleased("up")

Answer explanation

In Greenfoot Java, the isKeyDown() method is used to check if a specific key is currently being pressed. This method takes a string argument representing the key to check. It returns a boolean value of true if the specified key is currently being held down, and false otherwise. For example, if you want to check if the "Space" key is being pressed, you can use Greenfoot.isKeyDown("space").

In Greenfoot Java, which method is used to set the rotation angle of an object within the world?

• setAngle()

• rotate()

• turn()

• setRotation()

Answer explanation

In Greenfoot Java, the setRotation() method is used to set the rotation angle of an object within the world. This method takes an integer argument representing the desired rotation angle in degrees. The object will then be rotated to the specified angle. For example, if you want to set an object's rotation angle to 90 degrees, you can use the setRotation(90) method.

How do you add objects to your window?

• Select the class and hold shift to place multiple objects

• Right click on the class and select, add new instance

• Select the class and hold CTRL to place multiple objects

• Left click on the class and select, add new instance

In Greenfoot Java, which method is used to check if an object is currently touching another object of a specific class?

• isColliding()

• intersects()

• isTouchingObject()

• isTouching(Class cls)

Answer explanation

Example:

if(isTouching(leaf.class)) {

do something

}

In Greenfoot Java, which method is used to remove all objects of a specific class that are currently touching an object?

• removeObject(Class cls)

• removeTouching(Class cls)

• removeColliding(Class cls)

• removeIntersecting(Class cls)

Answer explanation

Example:

if(isTouching(leaf.class)) {

removeTouching(leaf.class);

}