unit 3 CP A

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 }

JavaScript

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 line

  circle.setRadius(40);

  JavScript

  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);

  JavaScript

  after line 4

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

var first_name = readLine("What is your first name? "); var last_name = readLine("What is your last name? "); var whole_name = first_name + last_name; println (whole_name);

• Fernandez Florence

• Florence Fernandez

• FlorenceFernandez

• Florence Fernandez

Which of the following choices is a properly formed JavaScript variable name, meaning it is both legal in the JavaScript language and considered good style?

• user_age

• UserAge

• userAge

• User age

If you wanted to use the following code to draw a circle to the canvas with the radius, and x and y coordinates given by the user, how would you ask for this information?

var circle = new Circle(radius); circle.setPosition(x, y); circle.setColor(color); add(circle);

• var x = readLine(“What is the x coordinate? “);var y = readLine(“What is the y coordinate? “);var radius = readLine(“What is the radius of the circle? “);

• var x = readInt(“What is the x coordinate? “);var y = readInt(“What is the y coordinate? “);var radius = readInt(“What is the radius of the circle? “);

• var x = readLine(“What is the x coordinate? “);var y = readLine(“What is the y coordinate? “);var radius = readInt(“What is the radius of the circle? “);

• var x = readInt(“What is the x coordinate? “);var y = readInt(“What is the y coordinate? “);var radius = readLine(“What is the radius of the circle? “);

If you were given the following variables:

var distance = 2; var time = 30;

What line of code would print the speed in km/hr if the distance is given in km and the time is given in minutes? (Speed = distance/time)

• println(distance/(time/60));

• println(distance/time);

• println(distance*(time*60));

• println(distance*time);

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

var num = 13 % 3; println(num);

• 1

• 2

• 3

• 4

var userNum = readInt("Enter your favorite number: "); var calculatedNum = (userNum * userNum) + userNum; println(calculatedNum);

• 5

• 25

• 30

• 50

var radius = readInt("What is the radius of the circle? "); var circle = new Circle(radius); circle.setPosition(radius, radius); add(circle);

• Draws a circle to the center of the canvas with size based on user inputted value

• Draws a circle on the canvas with the center positioned at the coordinate (0,0)

• Draws a circle that is positioned in the bottom right corner of the canvas

• Draw a circle on the canvas that always touches the top and left sides of the canvas

If a user enters a diameter value in the variable diameter, how would we use this to draw the correct sized circle?

• var circle = new Circle(diameter); circle.setPosition(100,100); add(circle);

• var circle = new Circle(diameter*2); circle.setPosition(100,100); add(circle);

• var circle = new Circle(diameter/2); circle.setPosition(100,100); add(circle);

• var circle = new Circle(diameter%2); circle.setPosition(100,100); add(circle);

A store has 20 apples in its inventory. How can you store this information in a JavaScript variable?

• var numApples == 20;

• 20 = numApples;

• var numApples = 20;

• var num apples = 20;