Unit 3 (Arrays) Review

Why are arrays useful?

• It saves storage space storing multiple values under one variable name

• You can store integers and strings together

• You can store data related to different topics

• You can store related data together rather than storing each value separately

All elements in an array must have exactly the same type.

• true

• false

How many lines of output will the following code produce?

• 5

• 6

• 9

• 12

How many lines of output will the following code produce?

• 5

• 6

• 9

• 12

After running the following code, what is the sum total of all the elements within values?

What does the following Java code print?

The goal of the method is to fill each entry in the arr array with the number of elements that follow it. For instance, if the input was an array of length 4, the returned array would be {3, 2, 1, 0}.

What should fill in the blank so that the method works as desired?

How many times will the body of this loop execute?

What values will be stored in the arr array after the following code executes?

• {0, 0, 0, 0, 0, 0, 0}

• {9, 9, 9, 9, 9, 9, 9}

• {9, 0, 0, 0, 0, 0, 0}

• {9, 0, 0, 9, 0, 0, 0}

• The code will cause an IndexOutOfBounds Exception

Suppose these classes have been defined. What will print when the following code executes?

Animal[] zoo = {new Bird(), new Sparrow(), new Animal()};

for (Animal animal: zoo) {

animal.eat();

}