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do you know what the question is infact? the question is to make the following methods without using prepared methods in String Class and operators += and +:
public String delete (String st, int startIndex, int len);
public String copy (String st, int startIndex, int len);
public String insert (String st1, String st2, int len);
public String concat (String st1, String st2);
public int pos (String st1, String st2, int len);
public int countOf (String st1, String st2, int len);
public String intToStr(int value);
public int strToInt (String value);
public String reverse (String value);
how can i answer to these question with considering the condition?
please help me and as you guessed it's a school homework.
thank you
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dont use the String class...use the string type...thats what i'd do, i would also call the professor a moron probably in class...which explains my excellent grades in college. and like everyone mentioned before, if you get stuck at some specific place ask here, we will not do you homework for you. most of us didnt have these kind of resources when we took those classes, or didnt use them for anything other than very spcific questions if we did.
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.
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SomeGuyThatIsMe wrote: dont use the String class...use the string type...
How do you thing the 'String class' and the 'string type' differ ? Whatever you think, you're mistaken.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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I assumed it was a trick question, and that they couldnt use the String class, but using string instead would work, since they work the same, his assignment would be easy. and since String is capitalized i assume its a class, and since string isnt and VS changes it color jus tlike other base types(int, double, char, etc..), i call it a type, even though it is a class just to tell them apart. bad behavior, but old habits are hard to break. i realize they arent different aside from that. but if it wasnt a trick question and he cant use a foreach, or indexes, or any member function he's pretty hosed..tho what about Convert? does it have a method to take strings to char[]'s i cant remember.
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.
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He could just use [] to access the chars and build whatever he likes.
String and string are the same thing. They are not two objects that look the same, they are the same object.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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SomeGuyThatIsMe wrote: since they work the same
They don't work the same. The ARE the same!
string is a synonym for System.String
SomeGuyThatIsMe wrote: since String is capitalized i assume its a class
And a class is a type.
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OK - so you have to assume that my answer was right. You CAN use foreach, and you can use [].
If you can't, then the question does not say that, AND, without those, it plain cannot be done.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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thanks for your answer but 'foreach' and indexes are not allowed to use, too. but i think when our teacher askes such questions, there should be a solution.
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Sajjad Izadi wrote: thanks for your answer but 'foreach' and indexes are not allowed to use, too.
you keep saying that, but:
1 - the question does NOT say that
2 - that means there is no solution. Except maybe prayer or voodoo magic.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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Sajjad Izadi wrote: i think when our teacher askes such questions, there should be a solution.
Could it be your teacher is an idiot?
"The clue train passed his station without stopping." - John Simmons / outlaw programmer
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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Christian Graus wrote: it plain cannot be done.
Hmm. All it takes is StringBuilder class, with one of its constructors (string), and ToString().
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Hmmm - I didn't think of that. I guess I was looking for educational value, I assumed he wanted them to learn about how to use array indexes. Plus, he's insisting he can't use stuff that the question doesn't say.
What a *dumb* thing for a teacher to assign, if the answer is to use a stringbuilder. But, wait, how would they get substrings, etc ? I mean, they would then need to call methods on the string class, via the string returned from ToString, right ?
I reviewed the assignment, and while there's no substring, there is a reverse, and other methods such as finding the index of a string in another, that make me think that a stringbuilder is definately not the answer being sought, and that addressing chars in a string by index, is.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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No string operations are required at all once the raw data is available, and that is what
new StringBuilder(string) does. So basically it is used as a replacement for
the index operator, allowing an almost native implementation of string functions.
I do agree it isn't a very smart assignment.
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You're saying there's a tostring on StringBuilder that takes indexes for substrings ?
That DOES make sense of not being allowed to use +, you don't need to.
How odd...
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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Christian Graus wrote: You're saying there's a tostring on StringBuilder that takes indexes for substrings ?
I did not intend to say that, but yes it does exist.
Anyway one does not need it, access to the raw data plus some character moving is all it takes.
Import with the SB constructor, export with a simple SB.ToString.
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He's not allowed to use foreach, I assume that means when he says he's not allowed to use [], he means at all, not just on the string class.
I bow to you, that just didn't occur to me, or anyone else.
I wonder if the goal is to fail anyone who gets the answer, b/c they must have asked on the web to get it ?
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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Maybe, but the teacher should be a bit more clear and should give the students a hint, such as "you may want to look at the stringbuilder class" 
"The clue train passed his station without stopping." - John Simmons / outlaw programmer
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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Oh, the assignment is useless. I think the main reason none of us got it is b/c it's not clear how you'd expect that to involve a learning objective. What do they learn from that ?
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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Christian Graus wrote: the assignment is useless
Yes. It was very pointless, and it is not something I would subject my students to.
Christian Graus wrote: What do they learn from that ?
Not sure, other than to try and get other people to do their work for them. That is why I suggested the teacher should have given some kind of hint.
"The clue train passed his station without stopping." - John Simmons / outlaw programmer
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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Five for you. I didn't even think of the StringBuilder class 
"The clue train passed his station without stopping." - John Simmons / outlaw programmer
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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Luc Pattyn wrote: All it takes is StringBuilder class, with one of its constructors (string), and ToString().
Oh, circumventing the rule that no methods of the string class should be used, by using methods of another class... Sneaky... 
Then there are some other alternatives to get at the data, like using the Encoding.UTF16.GetBytes method, or use a StreamWriter to write the string to a MemoryStream...
Despite everything, the person most likely to be fooling you next is yourself.
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Guffa wrote: Oh, circumventing the rule that no methods of the string class should be used, by using methods of another class... Sneaky...
Yeah, what's the use of .NET if you're not allowed to use any class method? 
And if that is what it takes to answer a question, then probably the question itself is sneaky.
I can't help that.
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An alternative, more adventurous, but all in all easier way is to use P/Invoke and some
native C code, so strlen, strcat, and the like can be used (they are not part of the String class!).
Now the input data can get passed down as string, and a sufficiently large StringBuilder
should be passed too to collect the resulting string, so ToString() can upgrade them to the
final result.
This way the exercise makes some sense.
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OK - I'm interested. Type in the EXACT text of the assignment so we can all marvel at this. You've got a site full of professional developers here all telling you that this can't be done so at least one of the following conditions applies:
a) your understanding is wrong
b) this is the wrong forum and you are meant to be using a language like C
c) you have missed out a vital step or two
d) your professor is a complete thundering idiot and the assignment is wrong
e) you are way off beam with the foreach/indexer idea
Let's have a look so we can make our own mind up.
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I think Luc found the answer. I can't imagine what the goal of this assignment was, in terms of learning something, but apparently, you can pass a string into a stringbuilder and use the stringbuilder to pull out substrings, and get the string length. You can use another stringbuilder to build a new string.
So, ultimately, the only thing I can think of, is that the professor hoped to create some research skills, or something.
Christian Graus
Please read this if you don't understand the answer I've given you. If you're still stuck, ask me for more information.
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