[Request] Help with codes

[xax0r]

Hi,

I  need help with codes on pictures in attachments. I need it "now" cause I must pass the exam of programming who's I hate. Thanks for help!

 

http://i45.tinypic.com/35na1zm.jpg

http://i50.tinypic.com/14wgm13.jpg

 

 

[IWillBeThere]

Hi,

I  need help with codes on pictures in attachments. I need it "now" cause I must pass the exam of programming who's I hate. Thanks for help!

 

http://i45.tinypic.com/35na1zm.jpg

http://i50.tinypic.com/14wgm13.jpg

 

we dont understand this language, translate exercises in english.

[vampir]

They are wrote in polish language, i know its been a while but maybe u will learn something:

1. What variables will print on the screen below fragment of the program?

int e[][]={{45,5,6},{7,9,4},{8,8,9}};
for(int x[]:e) for(int y:[x]) System.out.print(y);

ok so in first line we have got 2 dimensional table, first[] before e, are all variables inside {}, so e[1] will give us {7,9,4}, but we always need to write something in 2nd [], which means number inside {}.

e[0][1] will give us 5, e[2][2] will give us 9.

for(int x[]:e) - thats something harder, we have got a loop which will create for us 3, 1 dimensioned tables, so first we will have int[] x = {45,5,6}; later x will be {7,9,4} and at the end {8,8,9}; so if we would have something like this:

for(int x[]:e) System.out.print(x[0]);

4578 - would appear.

now for(int y:[ x ]) - that doesnt exist in java 1.7, it should be for(int y:x) - loop will create y variable for each number in the table.

So first (y=45,x=0), (y=5,x=0), (y=6,x=0), (y=7,x=1) etc

what we have at the last is System.out.print(y).

So we will have 4556794889 :)

 

2.Create new object of class B, run method and set any value to variable i

class A {int i=10 ; int metoda(){int b=10; return b; }}
class B extends A {int i ; int metoda(int t){byte b=10; return b+t;}}

B ob = new B(); - creating new object of class B

ob.i = 123; - setting any value to variable i

 

3.What implements function?

 void function(){ int n=10; int[][] tab=new int[n][];
for(int i=0;i<n;i++) tab[i]=new int[i+1];
System.out.println(tab.length); System.out.println(tab[n-1].length); }

So, int[][] tab=new int[n][]; - we are creating new 2 dimensional table, tab length will be now n(10)

for(int i=0;i<n;i++) tab[i]=new int[i+1];

tab[0] length will be 1, tab[1] length will be 2 etc.

System.out.println(tab.length); - will give us tab length = 10

System.out.println(tab[n-1].length); - will give us length of tab[9], it will be 10

 

4.What will be printed on the screen?

 void function(){ int n=4; for(int i=n;i>1;i--){ for(int j=0;j<i;j++)
System.out.print(" "); System.out.println("*");} }

for(int i=n;i>1;i--)

- this loop will work 3 times, 4>1, 3>1 and 2>1, in each case, 2nd loop will start

for(int j=0;j<i;j++)

- when i=4, this will work 4 times(j=0, j=1, j=2 and j=3), each time j is increased, to the screen is added " ", and each time i is decreased, "*" and skipping to next line is printed so it will be like this:

    *
   *
  *

 

5. What will appear on the screen?

public class rozne {
enum wyliczenie {Syrenka(500), Fiat125p, OpelCorsa(25000), Yaris(26000), Laguna(45000);
private int cena;
wyliczenie(int cena){this.cena=cena;}
wyliczenie(){ this.cena=-1;}
int cena()Preturn cena;}
}
public static void main(String[] args) {
for(wyliczenie x: wyliczenie.values())
odpowiedz(x);
}
static void odpowiedz(wyliczenie ob)
{
switch(ob)
{
case Syrenka : System.out.print("\t Samochod ="+ob);
case Fiat125p : System.out.print("\t Samochod ="+ob);break;
case Laguna : System.out.print("\t Samochod ="+ob); break;
}}}

Ok so, this is runned first:

for(wyliczenie x: wyliczenie.values())

so each value of enum Wyliczenie will be in variable x, first x=Syrenka, 2nd x=Fiat125p etc

each time method odpowiedz is runned, we are going to switch - putting our x(now ob) inside and we are checking if ob=Syrenka later if ob=Fiat125p and at the end if ob=Laguna

so, at the beggining ob is Syranka, so we are printing \t - thats Tabulator, Samochod=Syrenka.

But hey, we dont have a break after that, so its not being closed, we are printing it 2nd time, now our text will be like this:

	 Samochod =Syrenka	 	 Samochod=Syrenka

later into odpowiedz, we are putting Fiat125p, it is printed only once since after System.out.print is break;

we are not printing OpelCorsa because we dont have anything like that in switch

at the end it will be like this:

 Samochod = Syrenka	 Samochod = Syrenka	 Samochod = Fiat125p	 Samochod = Laguna

 

6. What's wrong with the code?

class A{int a; public A(int i){a=4*i;}
void pokaz(){System.out.print(a);}}
class B extends A{int b; public B(int i, int j){super(i); b=2*j;}}
public class Main{ public static void main(String[] args){
B ob = new B(3,5); A oa; A o=new A(3); oa.pokaz();}}

Whats wrong with the code? hmm or isnt initialized, u cannot use oa.pokaz() on null or not yet initialized reference :)

 

7. What will appear in the screen?

class A{int a=1; int b=2; public A(int i,int j){}
public A(A o){a=2*o.a; b=3*o.b;} void pokaz(){System.out.println(a+"_"+b);} }
public class Main { public static void main(String[] args) {
A oa= new A(0,0);A ob= new A(oa);A oc= new A(ob);oc.pokaz(); }}

ok so first, this is runned: A oa= new A(0,0); - we are creating new object, i=0, j=0 but inside {} we have got nothing, so we are going to next line:

A ob= new A(oa); - now we have got a=2*o.a(1) so a=2, b=3*o.b(2), so b=6

A oc= new A(ob); - same thing, a=2*2=4, b*3*6=18

oc.pokaz(); - "4_18" will be printed on the screen :)

 

Hope that i helped somebody :)

[Matim]

PL: Dobry sprawdzian xd

[vampir]

PL: Dobry sprawdzian xd

PL: Tez chcialbym takie miec :P