Summary of Class Presentation for June 15, 1999

	We started by looking at some examples of writing equals methods
for user developed classes.  In general, an equals method would take
a single parameter, an object of the same class.  Then the equals method
would contain a single return statement that would do ands (&&) of 
comparisons between corresponding data fields in the current object and 
the parameter object.  These comparisons would use == if the data field
was a primitive type ( byte, short, int, long, float, double, char, or 
boolean) and call the equals method for the corresponding class, if the
data field was itself an object.  If the data field was an array, a loop
should be used to compare corresponding elements in each array.
Of course, if the loop was needed, we could not write the equals method
as a single return statement.  Instead, we would need a boolean variable
to maintain the result of the comparisons as we executed a loop to do 
them.  This boolean variable would then be used in the return statement.

	We looked at Java flow of control.  Java control constructs are
basically the same as those in C and C++:  if, while, do-while, and switch.
There are two major differences, however: 
	1.  A new Java variable can be declared in any block including
	in the header for a for loop, but the name of that variable 
	cannot match that of any other variable that is active at that
	point;
	2.  Java supports the use of labels in continue and break 
	statements to allow branches out of nested loops to the outer
	loop headers.
  	
	A label is a name followed by a colon.  Labels may be placed only
on the headers of loops ( while, for, do-while).  A continue or break
statement then can specify the label, for example
	break outj;
where outj is a label.  Control would then jump to that header statement
just like when the bottom of that outer loop is reached during 
normal execution.  For a break, execution would proceed with the statement
following the labeled loop.  For a continue, execution would proceed 
with the next iteration of the labeled loop.