JavaScript Graphics

In a graphics canvas, what are the coordinates of the bottom right corner of the window?

• 0, 0

• 0, getWidth()

• getHeight(), getWidth()

• getWidth(), getHeight()

What are the coordinates of the center of the window?

• getWidth(), getHeight()

• getWidth() / 2, getHeight() / 2

• getHeight() - getWidth(), getWidth() - getHeight()

• getHeight() / 2, getWidth() / 2

In the following code:

var size = 20;

var x = 100;

var y = 200;

var ball = new Circle(size);

ball.setPosition(x, y);

What is the meaning of the x variable?

• The x coordinate of the center of the circle

• The x coordinate of the left edge of the circle

• The radius of the circle

• The position of the circle

The following program should draw a circle on the screen

1 function start(){

2 var circle = new Circle(40);

3 circle.setPosition(getWidth() / 2, getHeight() / 2);

4 circle.setColor(Color.blue);

5 }

But when we run this code, we don’t see the circle. What is missing from our start function?

• We never set the circle’s radius.We need to add the linecircle.setRadius(40);After line 4

• We are setting the position of the ball to be off the canvas.

  We need to change line 3 to be

  circle.setPosition(0, 0);

• We are creating the circle incorrectly. We need to specify the width and height.

  We need to change line 2 to be

  var circle = new Circle(40, 40);

• We create the circle and position it correctly on the screen, but we never add it to the screen.

  We need to add the line

  add(circle);

  after line 4

What is printed to the screen if the user enters ‘5’ when the following program is run?

var userNum = readInt("Enter your favorite number: ");

var calculatedNum = (userNum * userNum) + userNum;

println(calculatedNum);

• 5

• 25

• 30

• 50

What is the output of the following program: (Assume the user enters ‘Florence’ then ‘Fernandez’.)

• Fernandez Florence

• Florence

  Fernandez

• FlorenceFernandez

• Florence Fernandez

What is printed to the screen when the following program is run?

• 1

• 2

• 3

• 4

Which command will set the position of Circle on 100 x position and 75 on y position.

• circle.setPosition(75, 75);

• circle.setPosition(100, 100);

• circle.setPosition(100, 75);

• circle.setPosition(75, 100);

Which command will add the circle to the program.

function start(){

var circle = new Circle(); circle.setColor(Color.blue); circle.setPosition();

//missing code

}

• add(circle);

• add(circle)

• add(Circle);

• add(circle):

Which command get the 1/3 0f height of canvas when creating a rectangle:

• var rectHeight = Height() / 3;

• var rectHeight = getHeight() / 2;

• var rectHeight = getHeight() / 3;

• var getrectHeight = getHeight() / 3;