S A M P L E 

				  Quiz #4

Name ___________________   Honor Code________________________    Section _____
(Note: Getting your Name and Section right is worth one point. If we can't
decipher your name or section, it's wrong.)

A. Assume you have the following Java code fragment (part of the action
method) and it runs.  What is the value of total when it completes? _____6____
(doing a trace should help you...)

    int k, total = 0, start = 4, stop = 1;
    ...
    k = start;
    while (k > stop)
    {
	k = k - 1;
	total = total + k;
    }
    ...

Safest way to do (note that the trace below is NOT required, but it
might keep you from making a silly error.)

(1) int k, total = 0, start = 4, stop = 1;
    ...
(2) k = start;
(3) while (k > stop)
    {
(4)	k = k - 1;
(5)	total = total + k;
    }

	#	k	total	T/F
        1	?	0	?
	2	4
	3			T
	4	3
	5		3
	3			T
	4	2
	5		5
	3			T
	4	1
	5		6
	3			F

B. Here are some simple rules defining Java syntax.

1. <name> -> //any string of alphanumeric symbols that begins with a letter//
2. <statement> -> <name> = <expression> ;
3. <statement> -> <name> = new <class>(<arguments>);
4. <statement> -> <name>.<method>(<arguments>) | <method>(<arguments>) ;
5. <arguments> -> //possibly empty list of <expression>s separated by commas//
6. <expression> -> <string-expression> | <int-expression> | <oth-expression>
7. <string-expression> ->  <string-expression> + <string-expression>
8. <string-expression> ->  <string>
9. <string> -> "<i> any sequence of characters</i> "
10. <string> -> <name>
11. <method> -> setText|getText|getInt|setInt|add|actionPerformed|init
12. <compound-statement> -> {
                               //list of <statement>s//
                            }

In the style shown in the lectures, show how these rules can be used to
generate the following Java program fragment (thus verifying that it is
syntactically correct).  Identify the rule used at each stage.  Continue
on back (don't squeeze it all on this side).

	{
  	    memo = text + "water" ;
  	    next = "birth" + "day";
	}

Start with: #12	
12 <compound-statement> -> {
                              <statement>
                              <statement>
                           }

   <compound-statement> -> {
2                             <name> = <expression> ;
2                             <name> = <expression> ;
                           }

   <compound-statement> -> {
1                             memo = <expression> ;
1                             next = <expression> ;
                           }

   <compound-statement> -> {
6                             memo = <string-expression> ;
6                             next = <string-expression> ;

   <compound-statement> -> {
7                             memo = <string-expression> + <string-expression> ;
7                             next = <string-expression> + <string-expression> ;

   <compound-statement> -> {
8                             memo = <string> + <string-expression> ;
8                             next = <string> + <string-expression> ;

   <compound-statement> -> {
10                            memo = <name> + <string-expression> ;
9                             next = "birth" + <string-expression> ;

   <compound-statement> -> {
1                             memo = text + <string-expression> ;
                              next = "birth" + <string-expression> ;

   <compound-statement> -> {
8                             memo = text + <string> ;
8                             next = "birth" + <string> ;

   <compound-statement> -> {
9                             memo = <name> + "water" ;
9                             next = "birth" + "day" ;
                           }