APPROVED QUESTIONS AND ANSWER KEY!!
In the following code:
var ball;
function start(){
ball = new Circle(20);
add(ball);
setTimer(draw, 20);
}
function draw(){
ball.move(2, 2);
}
When will the function draw be called? correct answers Every 20 milliseconds
Which statement will call a function animate every 50 milliseconds? correct answers
setTimer(animate, 50);
9.1.5 Crazy Ball correct answers var RADIUS = 100;
var circle;
function start(){
circle = new Circle(RADIUS);
circle.setPosition(getWidth()/2, getHeight()/2);
add(circle);
setTimer(crazyBall, 100);
}
function crazyBall(){
var x = Randomizer.nextInt(RADIUS, getWidth()-RADIUS);
var y = Randomizer.nextInt(RADIUS, getHeight()- RADIUS);
circle.setPosition(x,y);
circle.setColor(Randomizer.nextColor());
}
What does this program do?
function drawCircle(x, y, radius, color){
var circle = new Circle(radius);
circle.setPosition(x, y);
circle.setColor(color);
add(circle);
}
function start(){
setTimer(draw, 50);
}
function draw(){
var color = Randomizer.nextColor();
var centerX = getWidth()/2;
var centerY = getHeight()/2;
var radius = 100;
drawCircle(centerX, centerY, radius, color);
,} correct answers Draws several randomly colored circles at the center of the canvas by
drawing 1 every 50 milliseconds.
Which statement would stop the timer in the following program?
function drawCircle(x, y, radius, color){
var circle = new Circle(radius);
circle.setPosition(x, y);
circle.setColor(color);
add(circle);
}
function start(){
setTimer(draw, 50);
}
function draw(){
var color = Randomizer.nextColor();
var centerX = getWidth()/2;
var centerY = getHeight()/2;
var radius = 100;
drawCircle(centerX, centerY, radius, color);
} correct answers stopTimer(draw);
9.2.5: Growing Circle correct answers var START_RADIUS = 1;
var INCREMENT = 1;
var CHANGE_COLORS_AT = 10;
var circle;
var MAX_RADIUS = 240;
var counter = 0;
function start(){
circle = new Circle(START_RADIUS);
circle.setPosition(getWidth()/2, getHeight()/2);
add(circle);
setTimer(draw, 50);
}
function draw(){
START_RADIUS = START_RADIUS + INCREMENT;
circle.setRadius(START_RADIUS);
counter++;
if(START_RADIUS % 10 == 0){
circle.setColor(Randomizer.nextColor());
}
if(counter == MAX_RADIUS){
stopTimer(draw);
}
}
9.2.6: Paint splatter correct answers var CIRCLES_PER_SPLATTER = 20;
var MIN_RADIUS = 5;
var MAX_RADIUS = 25;
var DELAY = 500;
/* This program creates a paint splatter.
, * It's art. */
function start(){
setTimer(splatter, 500);
}
function drawCircle(color){
var paint = new Circle(Randomizer.nextInt(5,25));
paint.setColor(color);
paint.setPosition(Randomizer.nextInt(0, getWidth()), Randomizer.nextInt(0, getHeight()));
add(paint);
}
function splatter(){
var color = Randomizer.nextColor();
for(var i = 0; i < 20; i++){
drawCircle(color);
}
}
Why do we want our code to be "reusable"? correct answers All of the above
How can we make our code reusable? correct answers All of the above
Which function has better reusability? correct answers function drawRectangle(x, y, width,
height, color){
//Draw a rectangle using the parameters as properties
...
}
9.3.5: Circle Wall correct answers // Constants
var RADIUS = 20;
var DELAY = 40;
// Define your global variables here
var yPos = RADIUS;
var xPos = RADIUS;
var counter = 0;
function start(){
setTimer(draw, DELAY);
}
function draw(){
var circle = new Circle (RADIUS);
circle.setPosition(xPos, yPos);
if(counter % 2 ==0){
circle.setColor(Color.red);
}
counter++;
add(circle);
xPos += 2*RADIUS;
if(xPos > getWidth()){
xPos = RADIUS;
yPos += 2*RADIUS;
}