CS 1713/1711 Introduction to Computer Science Laboratory 6

CS 1711 Recitation Laboratory 6:
Practice with Strings [10/12/99; 10/14/99; 10/19/99; 10/21/99]

Objectives:

Learn to use the String class.
Increase skills with writing and testing classes.
Introduction to the use of multiple constructors (polymorphism).

Note: variations on this problem are done in a Case Study in Chapter 3.6 (pages 102 and 103) and in Example 5.13 (pages 199 and 200). The book examples use SimpleGUI. This lab does NOT use SimpleGUI.

Check-off procedure:

You must attend the recitation and sign in. You are considered to be checked off if you make a reasonable effort to complete the lab. You should try to do most of this lab prior to lab time, so that you can ask questions of the TA.

Laboratory details:

Exercise I: Simple Pig Latin

Design and implement a class called PigLatin.

The class has two data fields:
- myEnglish is the English version of the string.
- myPigLatin is the Pig Latin version of the string.
The class has the constructor:
```
    public PigLatin(String english) {

    }
```
The class has the following accessor methods:
- getEnglish returns the English version of the string.
- getPigLatin returns the Pig Latin version of the string.
The class has a private helper function:
```
     private String translateWordSimple(String english) {
  
     }
```
translateWordSimple returns a string that is the simple Pig Latin translation of english as follows:
- If the string english starts with a vowel, no change is made and the original string is returned. To implement this part, you should add a private boolean function firstLetterIsAVowel (p. 201 of the text) to your class.
- If the string english starts with a consonant, return a new word formed by moving the consonant to the end of the word and adding "ay". For example, if english is the word "cat", the returned string is "atcay".
The helper function translateWordSimple is called from the constructor to set the value of myPigLatin.
Write a main standalone program to test this class.

Exercise II: Advanced Pig Latin:

Modify the PigLatin class as follows:
Add a second constructor:
```
    public PigLatin(String english, boolean advanced) {

    }
```
If the advanced flag is false, the constructor uses translateWordSimple to get the Pig Latin translation of the English word. If the advanced flag is true, the constructor uses translateWordAdvanced to get the Pig Latin translation.
Add a helper function:
```
     private String translateWordAdvanced(String english) {
 
     }
```
The helper translateWordAdvanced returns a new string representing the advanced Pig Latin translation of english.
- If english starts with a vowel or has no vowel, return a new word formed by adding "way" to the end of the word. For example, if english is the word "apple", a string "appleway" is returned.
- Otherwise, return the word formed by moving the characters before the first occurrence of a vowel to the end of the word and adding "ay" For example, if english is the string "strong", a string "ongstray" is returned.
- Add a helper function findFirstVowel(String english) that returns the position of the first vowel in english or -1 if english has no vowels. (This function will be written in class.)
The helper function translateWordAdvanced is called from the second constructor to set the value of myLatin when the advanced flag is true.
Modify your main test program to test the new cases.

Last revision: October 18, 1999 at 11:00 am.