Week 4: Week of Sept 17

Monday:

Overview of notebook.pld

	listReverse
	totallength
	longestNote
		note need to record POSITION of longest note
		Thus, a for:each loop could not be used.
		
	relation to min date (year or year/month)

MailServer: Iterator loop example [??]
Notebook: iterator loop (below)
Not on exam in any form.
Advantage: 

Search loop again

Loop types

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Notebook SEARCH loops:

javadoc and String page; find note.contains(s)

"return loop": use return statement to terminate when found
	isPrime was an example of this
	so was LabClass.searchStudent
	
"print all" loop: terminate at end of list, regardless of data found
	Notebook.searchNotes is an example
	
"find first" loop: compare to example on page 94
	
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   Iterator loop:
   	p 95
   	
   	Iterator<String> it = notes.iterator();
   	while(it.hasNext()) {
   		totallen += it.next().length();
   	}

MailServer iterator loop: 
Use iterator (or while) because we can remove an item from the list
being processed.

    public MailItem getNextMailItem1(String who)
    {
        Iterator<MailItem> it = items.iterator();
        while(it.hasNext()) {
            MailItem item = it.next();
            if(item.getTo().equals(who)) {
                it.remove();
                return item;
            }
        }
        return null;
    }

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max loop: finding longest note


loop patterns:
	processing a list
	processing a range of numbers 1..N
	processing N times
	
	printing or other repeated action
	sum
	search
	max


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Wednesday:

Auction system: more min/max loops
	Trivial classes: Person, Bid
	Simple classes:  Lot
	List class:	 Auction

Lots of use of "null" and of anonymous objects

	
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Auction system

	use of null to indicate unused fields
	what the fields do
	mostly record-keeping

	1. "Trivial" classes Person and Bid
		Could we use a String for Person? What about Bid?

	2  Lot: description, lotnum, highbid.
		Lotnum = position in Auction.lots

	4. Anonymous objects: 4.9.4
	

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Numeric example with max

	repeatedly calculate rand.nextInt(100)
	until we reach 1
	
	Count the # of iterations
	count the max
	
	Do it 1000 times and find max length
	
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Friday

Notes on labs:
	Over a third of you turned in the wrong file, or didn't attach a file!

Ctor in Membership: nobody asked about "throws IllegalArgumentException"!
That's probably a good thing, in that this "weird stuff" didn't confuse too much.

If Alice was the first member, you didn't check the month

                if (m.getYear() < minYear) {

versus:		
		if (m.getYear() < minYear || 
			(m.getYear() == minYear && m.getMonth() < minMonth))
			
min loop:
	ALWAYS need to update min_so_far
	depending on circumstances, may also need to keep track of 
	position of min_so_far in the list, or of entire min_so_far object
	
ArrayList<int> v ArrayList<Integer>, "autoboxing"

Arrays
	fixed size
	most efficient (but don't obsess about that)
	underlying basis for ArrayList
	A[i] notation
	
	logfile analyzer: how would we do it with an ArrayList?
	
	Allocating arrays v allocating array elements
	
	classic for-loops:
		initializing an array of ints to 0
		adding the elements of an array
		finding the max of an array
		counting selected elements of an array
		
	classic for-loops v for:each loops
	was the classic for-loop really *designed* for arrays?
	
	for:each loop: no access to the numeric position in the list!
	
	classic-for / while equivalence
	
	for:each and arrays
	
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