CMU Unit 2 Practice Test

Which of the following would be a legal function call for the given function definition for drawWords()?

• drawWords(20,'blue)

• drawWords(100, 100)

• drawWords('blue', 'red')

• drawWords('blue',20)

Answer explanation

The first parameter is color and the second parameter is a fontSize. So the order must be color then number. Only drawWords('blue',20) follows this order.

Which of the following are parameter(s) of the function drawWords() from question 1?

• color

• fontSize

• color and fontSize

• None of the above

Answer explanation

Parameters are the name of the variables that receive a value and can be used in the functions code. They are located in between the parenthesis in a function definition. Here, there are two parameters separated by a comma: color, fontSize

Which of the following are argument(s) of the Label function call inside the drawWords function definition?

• r.centerX, r.centerY, and r

• color, True, and r

• r.value and color

• None of the above

Answer explanation

Arguments are the specific values in a function call. Here, it says the function call is to the Label function (line 4). The following are arguments of the Label function call: r.value, r.centerX, r.centerY, fill=color, bold=True, and size=fontSize. Since none of the answer choices had all correct arguments, the answer was none.

What will be displayed on the screen when we call func()

• I pity the

• foo

• foo I pity the

• I pity the foo

Answer explanation

When we call func(), the first line of code in the definition is line 5. This is a function call to foo, so the program jump to line 1 and runs the foo() function. The foo function prints 'I pity the '. Then the program jumps back to line 5 and continues from there. It prints 'foo' on line 6 and is done.

How many shapes are drawn in the code shown?

• 4

• 7

• 8

• 12

Answer explanation

Each function call to drawShapes() will draw 4 shapes: a star, a regular polygon, a rectangle, and an oval. Since we call drawShapes() function 3 times on line 8, 9, and 10, a total of 12 shapes will be drawn: 3 stars, 3 regular polygons, 3 rectangles, and 3 ovals.

Which of the following is not a valid property of rectangles?

• right

• bottom

• translation

• fill

Answer explanation

All shapes have the following properties: left, right, top, bottom, centerX, and centerY, width, height, fill, border, borderWidth, opacity, dashes, rotateAngle, visible

Both circles in the following image have a red fill. What could be the opacity of the circle on the left?

• 10

• 15

• 30

• 55

Answer explanation

The circle on the left is more visible, which means that its opacity value is higher. The higher the opacity value, the more visible a shape will be. An opacity of 100 means that the shape is fully visible(normal) and an opacity of 0 means that the shape is not visible.

Which of the following correctly multiplies the centerY of rectangle called r by 10 and updates its value?

• r.centerY = 10

• r.centerY * 10

• r.centerY *= 10

• r.centerY =* 10

Answer explanation

To multiply and update a value, the correct syntax is variableName.property *= number. A common mistake is for students to write =*. Also, while r.centerY * 10 multiplies the center by 10, it does not update the value of centerY

What is the value of c.right after the mouse is pressed 15 times?

• 230

• 220

• 210

• 180

Answer explanation

This is the circle before any mouse presses. Since the center is (50, 50) and the radius is 20, then c.right returns the value 70. Pressing the mouse increases the radius by 10 each time, so pressing it 15 times increases the radius by 150. 70+150 = 220.

Which of the following is the correct way to bring an oval named o to the back of the canvas?

• toBack(o)

• back(o)

• o.toBack

• o.toBack()

Answer explanation

The correct syntax is shapeName.toBack()