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java string operation

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a
Guest

Posted: Mon Apr 25, 2011 7:18 am Post subject: java string operation

Hi I have 2 string containing login info. I need a reversible opertion to mix them together. e.g C = op(A, B) op'(C) -> A B Thanks

Luuk
Guest

Posted: Mon Apr 25, 2011 10:58 am Post subject: Re: java string operation

On 25-04-2011 11:18, a wrote:

Quote:

Hi

I have 2 string containing login info. I need a reversible opertion to
mix them together.
e.g
C = op(A, B)
op'(C) -> A B

Thanks

My javaskills are limited, and need refreshing ;)

I did a course 11 years ago, and never use java after that.....

public class TEST {

public static String op( String A, String B) {
int i;
i = A.length();
return i + "|" + A + "|" + B;
}

public static String op(String C, int D) {
int i,j;
String E = "";

i = 0;
j = 0;
while(C.charAt(i) != '|') {
j = j * 10 + C.charAt(i)-48;
i = i + 1;
}

if (D==1) {
i= i + 1;
j= i + j;
} else {
i= i + 2 +j ;
j= C.length();
}

for (int x=i; x<j; x++) {
E = E + C.charAt(x);
}

return E;
}

public static void main (String args[]) {

String A = "someusername";
String B = "someweirdpassword";
String C;
String D;

C = op(A,B);
System.out.println( C );
D = op(C,1);
System.out.println( D );
D = op(C,2);
System.out.println( D );
}
}

--
Luuk

Luuk
Guest

Posted: Mon Apr 25, 2011 11:06 am Post subject: Re: java string operation

On 25-04-2011 14:58, Luuk wrote:

Quote:

On 25-04-2011 11:18, a wrote:
Hi

I have 2 string containing login info. I need a reversible opertion to
mix them together.
e.g
C = op(A, B)
op'(C) -> A B

Thanks

My javaskills are limited, and need refreshing ;)

I did a course 11 years ago, and never use java after that.....

public class TEST {

public static String op( String A, String B) {
int i;
i = A.length();
return i + "|" + A + "|" + B;
}

public static String op(String C, int D) {
int i,j;
String E = "";

i = 0;
j = 0;
while(C.charAt(i) != '|') {
j = j * 10 + C.charAt(i)-48;
i = i + 1;
}

if (D==1) {
i= i + 1;
j= i + j;
} else {
i= i + 2 +j ;
j= C.length();
}

for (int x=i; x<j; x++) {
E = E + C.charAt(x);
}

return E;
}

public static void main (String args[]) {

String A = "someusername";
String B = "someweirdpassword";
String C;
String D;

C = op(A,B);
System.out.println( C );
D = op(C,1);
System.out.println( D );
D = op(C,2);
System.out.println( D );
}
}

btw, i hope someone will post some recommendations on this 'code'....

;)

--
Luuk

Ian Shef
Guest

Posted: Mon Apr 25, 2011 6:11 pm Post subject: Re: java string operation

"a" <a (AT) mail (DOT) com> wrote in news:W%atp.7637$_P6.4055 (AT) newsfe05 (DOT) iad:

Quote:

Hi

I have 2 string containing login info. I need a reversible opertion to mix
them together.
e.g
C = op(A, B)
op'(C) -> A B

Thanks

Because Java cannot return two results with a single expression, this:
op'(C) -> A B
is completely unclear to me.

My suggestion is below. If you ignore equals, hashCode, toString and main,
it is really quite simple. I hope that I am not solving someone's homework
problem!

public class MixTogether {

private String a ;
private String b ;

MixTogether(String a, String b) {
this.a = a ;
this.b = b ;
}

public static MixTogether op(String a, String b) {
return new MixTogether(a, b);
}

public String getA() { return a ; }
public String getB() { return b ; }

@Override
public boolean equals(Object obj) {
if ( !(obj instanceof MixTogether)) return false ;
MixTogether m = (MixTogether)obj ;
return m.getA().equals(a) && m.getB().equals(b) ;
}
@Override
public int hashCode() { return toString().hashCode() ; }
@Override
public String toString() { return a + b ; }

public static void main(String [] args) {
String login = "login" ;
String password = "password" ;
MixTogether c = op(login, password) ;
System.out.println("c=" + c) ;
System.out.println("a=" + c.getA()) ;
System.out.println("b=" + c.getB()) ;
}
}

Inline
Guest

Posted: Mon May 23, 2011 6:43 am Post subject: Re: java string operation

Ian Shef wrote:

Quote:

"a"<a (AT) mail (DOT) com> wrote in news:W%atp.7637$_P6.4055 (AT) newsfe05 (DOT) iad:

Hi

I have 2 string containing login info. I need a reversible opertion to mix
them together.
e.g
C = op(A, B)
op'(C) -> A B

Thanks

Because Java cannot return two results with a single expression, this:
op'(C) -> A B
is completely unclear to me.

My suggestion is below. If you ignore equals, hashCode, toString and main,
it is really quite simple. I hope that I am not solving someone's homework
problem!

public class MixTogether {

It's possible to return both strings as an array. It is a bad idea to
put a password in a String. Because that String will than happily live
in the String pool, a char[] would be more appropriate.

class MyStrings {

private String[] originalStrings = new String[2];

public void setStrings(String a, String b){
originalStrings[0] = a;
originalStrings[1] = b;
}

public String getMixed(){
return originalStrings[0] + originalStrings[1];
}

public String[] getOriginalStrings(){
return originalStrings;
}

public static void main(String[] args){
MyStrings m = new MyStrings();
m.setStrings("sys", "admin");
for(String s: m.getOriginalStrings()){
System.out.println(s);
}
System.out.println(m.getMixed());
}

}

Ian Shef
Guest

Posted: Mon May 23, 2011 4:56 pm Post subject: Re: java string operation

Inline <a@a> wrote in news:4dda1e1a$0$49175$e4fe514c (AT) news (DOT) xs4all.nl:

Quote:

Ian Shef wrote:
"a"<a (AT) mail (DOT) com> wrote in news:W%atp.7637$_P6.4055 (AT) newsfe05 (DOT) iad:

Hi

I have 2 string containing login info. I need a reversible opertion to
mix them together.
e.g
C = op(A, B)
op'(C) -> A B

Thanks

Because Java cannot return two results with a single expression, this:
op'(C) -> A B
is completely unclear to me.

My suggestion is below. If you ignore equals, hashCode, toString and
main, it is really quite simple. I hope that I am not solving
someone's homework problem!

public class MixTogether {

It's possible to return both strings as an array.
I agree, but it is not nearly as clear and expressive as getLogin() and

getPassword() would be. I used getA() and getB() because A and B are the
names that the original poster used.

Quote:

It is a bad idea to
put a password in a String. Because that String will than happily live
in the String pool, a char[] would be more appropriate.
I agree, but the original poster defined the problem in terms of "string"

[sic].

Quote:

class MyStrings {

private String[] originalStrings = new String[2];

public void setStrings(String a, String b){
originalStrings[0] = a;
originalStrings[1] = b;
}

public String getMixed(){
return originalStrings[0] + originalStrings[1];
}

public String[] getOriginalStrings(){
return originalStrings;
}

public static void main(String[] args){
MyStrings m = new MyStrings();
m.setStrings("sys", "admin");
for(String s: m.getOriginalStrings()){
System.out.println(s);
}
System.out.println(m.getMixed());
}

}

This solution still has the String pool issue, and it is unclear at the end
what is login and what is password. Furthermore, returning originalStrings
breaks encapsulation.

I admit that it is a valid response to the original poster's request,
because the request was unclear and open to multiple interpretations, and
the original poster has not posted a clarification that is visible to my
news feed.

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