600.107 Intro Prog. in Java			
Practice Test3

1 -----------------------------

	What is the output of the following program?  
	Show the contents of memory for partial credit.

class test3a {
public static void main (String[] args) {
	char [] ra1 = {'c', 'd', 'e', 'f', 'c'};
	char [] ra2 = {'a', 'b', 'c', 'b', 'a'};

	if (tester(ra1, 0, ra1.length-1))
		System.out.println(ra1);
	else 	System.out.println("ra1 fails test");
	if (tester(ra2, 0, ra2.length-1))
		System.out.println(ra2);
	else	System.out.println("ra2 fails test");
}

public static boolean tester (char [] ra, int start, int end) {
	if (start > end) return true;
	if (start == end) return true;

	if (ra[start] != ra[end]) return false;
	else return tester(ra, start+1, end-1);
}
}







2 -----------------------------

	Write a static RECURSIVE method which has a single integer parameter and
	prints the integers from that number to 0 in descending order.  If the
	method is called with a negative number, it should do nothing.  If
	it's called with 0, it should print 0.  If it's called with 5, it
	should print 5 4 3 2 1 0.















3 -----------------------------

	Write a statement (as it might appear in main) to call the method
	above in order to output the integers from 10 to 0.







4a -----------------------------
Given the following array, what does it look like in memory
after the first pass of the outer loop of a SELECTION SORT?
(The inner loop will fully execute one time.)  Circle one choice.

	r = {25, 40, 13, 7, 90}  after 1st pass:



4b ------------------------------

Given the following array, what does it look like in memory
after the first pass of the outer loop of a BUBBLE SORT.
(The inner loop will fully execute one time.)  

	r = {25, 40, 13, 7, 90}  after 1st pass:



5a ----------------------------------

	Given the following array, what numbers would be looked at (in what
	order) during a BINARY SEARCH for the number 15? 

	r = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}




5b ----------------------------------

	Given the following array, what numbers would be looked at during a
	LINEAR SEARCH for the number 20?

	r = {23, 13, 29, 31, 20, 30, 12, 24, 90}






6 -----------------------------

	Assuming you have a sorted array, which type of search is usually
	faster (ie, faster in the worst case), binary search or linear search?




7 -----------------------------

	What is the base class (parent) of all classes in Java?



8a -----------------------------

 Which 3 methods from the Object class should all your classes override?


8b -----------------------------

 Which classes below have an inheritance relationship?  Indicate which
 are the subclasses and which are the superclasses.

 student		teacher

 student		teaching assistant

 blue jay		bird


9a ------------------------------

 Which Java interface contains the compareTo method? 


9b -----------------------------


True	False	1) A class can implement multiple interfaces in Java.

True    False   2) A class can inherit from multiple classes in Java.

True    False   3) A class can be the base class of many classes in Java.

True    False   4) Inheritance is referred to as an "IS-A" type relationship.

True 	False 	5) If a class implements an interface, it can pick and choose 
		   which methods from the interface to provide a definition for.

True    False   6) Protected access enables subclasses to access members of 
		   their superclass.


THERE WILL BE MORE QUESTIONS ON INHERITANCE, INTERFACES AND EXCEPTIONS
STARTING SUMMER 2005, BUT I DON'T HAVE SAMPLE QUESTIONS FOR THESE TOPICS.