WorksheetsJavaScript and Graphics
Total questions: 15
Worksheet time: 30mins
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;
You want to read input from the user to know how many apples they would like to buy. Which statement should you use to read in a number from the user?
var applesToBuy = readLine("How many apples would you like? ");
var applesToBuy = println("How many apples would you like? ");
var applesToBuy = readInt("How many apples would you like? ");
var applesToBuy = nextInt("How many apples would you like? ");
You are splitting up all of your apples equally between 3 people. Which statement below will calculate how many apples will be left over?
var leftOver = numApples / 3;
var leftOver = 3 / numApples;
var leftOver = numApples % 3;
var leftOver = 3 % numApples;
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 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
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 does the following program do?
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 is always tangential to 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);
