Java OOP / Advanced Programming

Skin10

CA591 - Object Orientated Programming repeat
Hi

Was looking for help with semester 1 2012 OOP exam paper. I have gone over it but looking for the answers so i can see where i went wrong.
Any help would be great.
Link to paper .
https://www.dcu.ie/internal/examinations/papers.php3?subj=CA591&portal=CA591paper

Also looking at the Semester 2 Advanced paper if any one did this and passed would appreciate it also.

Regards

Skylinehead

I'll do the first question now. No guarantees on the others, later maybe

a)
1. False
2. True
3. False
4. True I think, false and false = true?

b)

public boolean isPositive (int x)
{
if (x > 0)
return true;
else return false;
}

c)

public int maxNumber (int x, int y)
{
if (x >= y)
return x;
else return y;
}

* assuming of course the maximum of two integers is the biggest one? Badly worded question.

d)

public int numDivisors (int x)
{
int count = 0;
for (int divisor = 2; divisor < x; divisor++)
{
if (x % divisor == 0)
count++;
}
return count;
}


Boards is wrecking my indentation, hope you get the jist.

Skin10

Regarding 1a

I had
1:False ( 0 not = 0 is false as 0 == 0 )
2True ( if both operators are true then the answer is true when using &&)
3:True ( unless both operators are both false ) other wise always true..
4:True( Not False= is True i think) & false & True ( Not Sure)
5:True ( False == False)

1b

public boolean isPositive( int x)\\i left out the public ( so not sure if that was correct)\\
if ( x>0)
return true
else
Return false

1c
Not sure as the wording is funny.
I thought they were looking for the max of both numbers so i had the following.

public int Totalnum(int x,int y, int total)

int total = x+y
return total
but if it was the max of both int values then i would have answered the same.


1d

Skin10

Any one out there any more help on the above exam paper..

Skylinehead

Q2 a)

i
s
s
r
i
s

b)

public static int shortestWord (String s)
{
String[] splitWords = s.split(" ");
int shortest = splitWords[0].length();

for(int i = 1; i < splitWords.length; i++)
{
if(splitWords.length() < shortest)
{
shortest = splitWords.length();
}
}
return shortest;
}

http://pastebin.com/QRfp82fs for correct indentation.

tod48

hello , did you get my private message

avgwhitedude

any answer for question 4c ?? and explanation?

ozt9vdujny3srf

def you_can_use()
    'Code Tags to rpotect your indentation. 
}

tod48

Why are you so concerned about the answers to these questions ?The repeat exam will hardly be the same

Skin10

Thw repeat exam will not be the same but after talking with Ray last week he told me to go over the last exam as it will not change much at all ..

tod48

can i get your number please

Skin10

Q3
Any help on below

public televisionChannel (String Name,int number,Boolean HDTV)
{
String Name "";
Int number = 0;
Boolean HDTV =false;
}
Getter/Assessor

public String getName()
{
Return name;
}
public int getNumber()
{
return number;
}
public boolean getHDTV()
{
return false;
}

Setter/Mutators

public void setName(String name)
{
this.name=name;
}
public void setNumber(int number)
{
this.number=Number;
}
public void setHDTV (boolean HDTV)
{
this.HDTV=HDTV;
}

tod48

the mutators dont need "this" and the hdtv is type......

ohnonotagain

Hi,
I'm also doing the repeat exam and have been unable to get in touch with the lecturer re what to expect. I am going over the past paper also and hoping that should cover me. !!

Ishmael

public class TeleChan {

	
	private String name;
	private int number;
	private boolean hdtv;
	
	//Question 3A Default Constructor
	public TeleChan() {
		super();
		this.name = "";
		this.number = 0;
		this.hdtv = false;
	}

	//Question 3B - Constructor using parameters
	public TeleChan(String name, int number, boolean hdtv) {
		super();
		this.name = name;
		this.number = number;
		this.hdtv = hdtv;
	}

	// Question 3 C & D - Getters and Setters, Accessors and Mutators
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getNumber() {
		return number;
	}

	public void setNumber(int number) {
		this.number = number;
	}

	public boolean isHdtv() {
		return hdtv;
	}

	public void setHdtv(boolean hdtv) {
		this.hdtv = hdtv;
	}

	//Question 3E - toString Method
	@Override
	public String toString() {
		return "TeleChan [name=" + name + ", number=" + number + ", hdtv="
				+ hdtv + "]";
	}

	//Question 3F - equals method
	public boolean equals(TeleChan aTeleChan)
	{
		boolean result = false;
		
		if((aTeleChan.getName().equals(this.name)) && (aTeleChan.getNumber() == this.number) && (aTeleChan.isHdtv()==this.hdtv))
		{
			result = true;
		}
			
		return result;
        }

	//Question 3G - Return number of digits
	public int numDigits()
	{
		String newString = ""+this.number;
		return newString.length();
	}

	//Question 3H - Return String if HD or not
	public String isDigHDTV()
	{
		if(this.hdtv)
		{
			return "Digital T.V.";
		}
		else
		{
			return "Analogue T.V.";
		}
	}
		
}

Skin10

Yea i have not had any ore response from Ray since the first call.
I am going over the past papers also.

i am on on Q4 2012

The first run trough with out brackets

Q4a

a : 17.8
b: 6
c:5.57143
d:10
e:10.5

with Brackets
????


Q4b
When i first saw this in the exam i went on a mad tangent but after messing around with for loops its only 6 lines of code..

draw the star thingy

public class starprint
{
public static void main(String [] args)
{
for (int i=0;i<6;i++)
{
for(int j=i;j>0;j--)
System.out.print("*");
System.out.println();
}
}
}

Q4c
What will be the values of (i) m, (ii) nums[m] and (iii) count after the code
has executed?
[

After looking at the code and then after trying to run it i noticed loads of errors in the code .
So i am guessing this was a trick question as it would not run or just a miss print , so not sure of out put..

int count = 0;
[]int nums = { 21, 10, 15, -10, 10, 5, 8, 10, 3, 12);// should it not be
int [] nums ? and the start has a curley bracket the finish has a normal bracket.

int m = 0;
for(int i = 1; i < nums.length; i = i + 1)
if (nums < nums [m])
{
count = count + 1;
m=i
}

Skin10

Can you trace through your answer still trying to get this one ..

Skin10

Skylinehead wrote: »

Q2 a)

i
s
s
r
i
s

b)



http://pastebin.com/QRfp82fs for correct indentation.

can you trace through your answer , still trying to get this one..

ohnonotagain

Thanks Ishmael:D
I am answering myself and will compare my answers to yours to make sure I'm on right track.

However, regarding question one I think I got different answers to the guys earlier
1. false 2.true. 3. true 4.false 5.true

the last two questions there iv and v

iv true and false and true = false (because they are not all equal)?
v.both of these in brackets are false so both are equal which is true?
thanks a million

ohnonotagain

the array length or 'capacity' is eight starting at zero.

int len = 6 so draw a diagram and put an x over the box nr six

in box zero one and two put mon and tues and wed
in box len-1....go to 6th index (ie 7th place) and go back one and put thurs
in this box go back another and put friday and back another and put in saturday.

so your boxes (or your array) has mon tues wed sat fri thurs and the rest are empty.

change mon to friday so index o is now fri also.

no it says trace through the length and get the character at position -4 from the last letter of each word. hence if you count saturday y is -1 a is -2 d is -3 and r is -4.

ohnonotagain

"
i am on on Q4 2012

The first run trough with out brackets

Q4a

a : 17.8
b: 6
c:5.57143
d:10
e:10.5

with Brackets
????
"

this question should be easy but a bit confusing...

a) 21-16 = 5 and 5/5 equal to 1

b) 5/9/2 (after adding 7+2)?????

c) 21/7 is equal to three

d) 2*4*3 is equal to 12"

e) 42/4 is equal to 10.5

I haven't used brackets either. I know there is a rule ie do the addition and multiplication before disivion or subtraction. Here I just did what was easiest so anyone know the rules??? I think you can put the brackets wherever you like to get the answers you want so perphaps theoreticallly we have put the brackets where we want to work it out but not followed the rules for the first part of the question???? I'm taking a break now for a bit but will check back later.:cool:

Ishmael

Question 4 a)

21 - 16 / 5 = 18 - truncation occurs due to division of two ints. I.E. 16 / 5 = 3 and not 3.2.
(21 -16)/5 = 1

---

5.0 / 2 + 7 / 2 = 2.5 + 3 = 5.5
5.0 / (2 + 7) / 2 = 0.277777778

---

3.0 + 18 / 7 = 3.0 + 2 = 5
(3.0 + 18) / 7 = 3

---

2 * 2 + 2 * 3 + "" = 10
2 * (2 + 2) * 3 + "" = 24

---

6 * 7 / 4 = 10
6 * (7 / 4) = 6

---

I think they are correct but i may be wrong. If you ever right real code without proper parenthesis, you should be shot.

I tested these and it seems that the numbers are truncated but it depends on whether you are expected to account for this
or not in your exam.

=====================================


Question 4 b)

for(int i=0;i<=5;i++)
{
for(int j=0;j<i;j++)
{
System.out.print("#");
}
System.out.println("");
}

//prints a # symbol if j is < i, prints a return character when i = j. i varies from 1 to 5.

=========================================

Question 4 c)

m = 3
nums[m] = -10
Count = 2

Skin10

good luck to all 2moro ,