Cumulative Test Practice Units 1, 3, 4, 5, & 7

function mystery() {

while (noBallsPresent()) {

move();

}

}

• Karel moves until it is on a ball

• Karel moves once if there is no ball present

• Karel moves until it puts down a ball

• Karel checks if there is no ball on the current spot and then moves once

What condition should be used in this while loop to get Karel to pick up all the tennis balls on the current location?

while (________) {

takeBall();

}

• noBallsPresent()

• ballsPresent()frontIsClear()takeBall()

• frontIsClear()

• takeBall()

What’s wrong with this code?

function start() {

move();

go();

go();

}

function go() {

move();

move();

}

function go() {

move();

move();

}

• The go function is called twice

• The go function has a syntax error

• The go function has been defined twice

• go is not a command that Karel understands

What is wrong with this for loop?

for (var i = 0, i < 10, i + 1) {

move();

}

• The for loop uses commas instead of semicolons

• It should say i++ instead of i + 1

• Both A and B

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 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

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 = 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 = 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? “);

What will the following code segment evaluate to?

function start(){

var a = 10;

var b = 5;

var c = 2;

var expression = ((a - b) * c) % 3;

println(expression);

}

• 7

• 5

• 3

• 1

On the AP exam, the ← operator is used for variable assignment like the =. For example, a ← 10,, the arrow

assigns the value 10 to the variable a. The value stored in a variable will always be the most recent value assigned. Consider the following code segment.

a ← 12

b ← 3

c ← 27

a ← b

b ← c

c ← a

What value is stored in variable c?

• 3

• 9

• 27

• 81

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 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

• We never set the circle’s radius.

  We need to add the line

  circle.setRadius(40);

  After line 4

• 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);

What is the output of the following program?

function start(){

var x = 5;

sumTo(x);

println(x);

}

function sumTo(num){

var sum = 0;

for(var i = 0; i <= num; i++){

sum += i;

}

println(sum);

}

• 5

• 15

• 5

  15

• 15

  5