GROUNDWORK
Chapter 8 - Strings as Data

Name: ________________________________     Date: ______________

Fill in every blank. Where a term is asked for, write the word the course
uses. Where code is asked for, write exact Java. Where output is asked
for, write what the program prints, one line per line.


VOCABULARY
----------

 1. A String is a __________________ of characters, so charAt and
    substring count its positions from zero, as an array's indexes do.

 2. Unlike an array, a String is __________________: it cannot be changed
    after it is created, so every String method that seems to change it
    gives back a new String instead.

 3. The String method __________________ gives back true when another
    String appears anywhere inside it, and false when it does not.

 4. Sequences like \n and \t, which stand for characters that can't be
    typed directly into a string, are called __________________
    sequences.


READING CODE
------------

 5. What does this print?

        String word = "Java";
        IO.println(word.substring(0, 3));
        String reversed = "";
        for (int i = word.length() - 1; i >= 0; i--) {
            reversed += word.charAt(i);
        }
        IO.println(reversed);

    ____________________________________

 6. What does this print?

        String messy = "   Ada LOVELACE  ";
        String clean = messy.strip().toLowerCase();
        IO.println("[" + clean + "]");

    ____________________________________

 7. What does this print?

        String answer = " Yes ";
        IO.println(answer.equals("yes"));
        IO.println(answer.strip().toLowerCase().equals("yes"));

    ____________________________________

 8. What does this print?

        String row = "Ada,88,A";
        String[] fields = row.split(",");
        String name = fields[0];
        String score = fields[1];
        String grade = fields[2];
        IO.println(name + " scored " + score + " for a " + grade);

    ____________________________________

 9. What does this print?

        String word = "java";
        word.toUpperCase();
        IO.println(word);

    ____________________________________

10. What does this print?

        int countVowels(String text) {
            String lower = text.toLowerCase();
            int count = 0;
            for (int i = 0; i < lower.length(); i++) {
                char letter = lower.charAt(i);
                if ("aeiou".indexOf(letter) >= 0) {
                    count++;
                }
            }
            return count;
        }

        void main() {
            IO.println(countVowels("Hello World"));
        }

    ____________________________________


WRITING CODE
------------

11. Complete the line so that it prints the word in capitals:
    String word = "hello";
    IO.println(word.__________________()); // HELLO

12. Complete the line so that it splits the sentence into an array of its
    words:
    String sentence = "the quick brown fox";
    String[] words = sentence.__________________(" ");
    IO.println(words.length); // 4

13. Complete the line so that it glues the words together with a space
    between each one:
    String[] words = {"the", "quick", "brown"};
    IO.println(String.__________________(" ", words)); // the quick brown


WHY IT WORKS
------------

14. word.toUpperCase() by itself does not change word, because a String
    is __________________; every String method that seems to change it
    gives back a __________________ String rather than changing the
    original.

        String word = "java";
        word.toUpperCase();
        IO.println(word);

15. indexOf(x) gives back __________________ when x does not appear in
    the String at all; a result of __________________ means the match
    starts at the very first character.