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0) Administrative
- hw: read 8.1-8.2
- questions about A3?

1) Last time- started strings, learned a bunch of methods

Exercise: write pieces for a pig latin translator using these methods
		Hello. What street is that?
		ello-Hay. at-Whay eet-stray is-ay at-thay?

	- a helper to finds the index of the first vowel in a word
	- a method to turn a single word into pig latin
	- a helper to tell whether a character is a letter or not
	
	private int firstVowel(String word) {
		word = word.toLowerCase();
		for (int i=0; i<word.length(); i++)
			if (word.charAt(i)=='a' || word.charAt(i)=='e' ||
			    word.charAt(i)=='i' || word.charAt(i)=='o' ||
			    word.charAt(i)=='u')
				return i;
		return 0; // If no vowels, just be safe
	}

	private String pigWord(String word) {
		int split = firstVowel(word);
		return word.substring(split)+"-"+word.substring(0, split)+"ay";
	}

	private boolean isLetter(char c) {
		return ( (c >='A' && c <='Z') || (c >='a' && c <='z') );
	}

2) Go over 9.5-9.6 in your groups

3) Highlights

	A. Comparing strings
		- references: ==    contents: equals()
		- exception: literal strings are like primitives
			String a = "hi", b = "hi";
			if (a == b) // will be true
		- but as soon as you do anything with it, this changes
			a = a.toLowerCase();
			if (a == b) // not true anymore
		- this is weird and inconsistent, so don't rely on it

	B. StringBuffers: like Strings, except mutable
		- has methods that allow you to change it in place

		- make one (like a wrapper class for a string)
			StringBuffer sb = new StringBuffer("cat");
		- change characters
			sb.setCharAt(2, 'd');   -> "cad"
		- insert characters or strings
			sb.insert(1, 'h');      -> "chad"
			sb.insert(3, "ra");	-> "charad"
		- stick characters or strings on the end
			sb.append('e');         -> "charade"
			sb.append("s");		-> "charades"
		- delete characters
			sb.deleteCharAt(1);	-> "carades"
		- reverse string
			sb.reverse();		-> "sedarac"
		- extract the String out of it
			sb.toString();		-> returns the String

		- some others; many of the same ones that String has
		- you'll be given a list if you need it
	
	C. Things to remember
		- converting back and forth b/w SB and String
		- don't call methods on characters		

4) Finish PigLatin exercise
- the hard part: putting it all together
- come up with a pseudocode outline first, work out problems
- use StringBuffer just for practice

  private String pigLatin(String s) {
    StringBuffer latin = new StringBuffer("");
    int i = 0;
    while (i<s.length()) {

      // Take care of punctuation and spaces
      while (i<s.length() && !isLetter(s.charAt(i))) {
        latin.append(s.charAt(i));
        i++;
      }

      // If there aren't any words left, stop.
      if (i>=s.length()) break;

      // Otherwise we're at the beginning of a word.
      int begin = i;
      while (i<s.length() && isLetter(s.charAt(i))) {
        i++;
      }

      // Now we're at the end of a word, so translate it.
      int end = i;
      latin.append(pigWord(s.substring(begin, end)));
    }
    return latin.toString();
  }

5) Summary
- comparing Strings
- using StringBuffers

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