IST CodeHS Unit 8 JavaScript Review

If the user enters a diameter value in the variable called 'diameter', how can we use this value to draw a circle with the correct diameter?

• var c1 = new Circle(diameter/2)

• var c2 = new Circle(diameter)

• new Circle(diameter*2)

• var c3 = new Circle()

When prompted for two inputs, the user enters 'Kyle' and then 'Davis'. What is printed by this JS code?

var first = readLine("What is your first name? ");

var last = readLine("What is your last name? ");

var whole = first + last;

println(whole);

• whole

• KyleDavis

• Kyle Davis

• Davis Kyle

What are the x,y coordinates of the center of the canvas?

• 0, 0

• getWidth(), getHeight()

• getWidth()/2, getHeight()/2

• 0, getHeight()*2

What are the x,y coordinates of the bottom right of the canvas?

• 0, 0

• getWidth(), getHeight()

• getWidth()/2, getHeight()/2

• 0, getHeight()*2

If the user enters a radius value in the variable called 'radius', how can we use this value to draw a circle with the correct radius?

• var c1 = new Circle(radius/2)

• var c2 = new Circle(radius)

• new Circle(radius*2)

• var c3 = new Circle()

What does this code do?

var rad = readInt("Enter the radius: ");

var c = new Circle(rad);

c.setPosition(getWidth()/2, rad);

add(c);

• Draws a circle at the center of the canvas with a user inputted radius

• Draws a circle with center at (0, 0)

• Draws a circle with custom size that is centered and tangent to the top of the canvas

• Draws a circle with a random radius at the top of the canvas

var circle = new Circle(16);

What is the meaning of the above code?

• Creates a circle object with radius 16 pixels

• Draws a circle with center at (0, 0)

• Creates a circle object with center at (0, 16)

• Creates a circle object with circumference of 16 pixels

What is the meaning of the y variable?

var size = 20;

var x = 100;

var y = 150;

var ball = new Circle(size);

ball.setPosition(x, y);

• The x coordinate of the center of the circle

• The y coordinate of the center of the circle

• The radius of the circle

• The position of the circle

What is the meaning of the r variable?

var r = 50;

var x = getWidth()/2;

var y = getHeight()/2;

var cir = new Circle(r);

cir.setPosition(x, y);

• The x coordinate of the center of the circle

• The y coordinate of the center of the circle

• The radius of the circle

• The position of the circle

We want to draw a circle on the canvas. The following code is given: what is missing?

function start() {

var circle = new Circle(40);

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

circle.setColor(Color.blue);

}

• add(circle);

• circle.setPosition(0, 0)

• circle.setRadius(100);

• new Circle(center);