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BTW this is not my Homework, i have written the lines needed to reverse and display the string in the console. but i cant manage to RETURN a REVERSED String!!
Cheers 
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If you can reverse the string and display it in a console, then it should be pretty easy to return the reversed string.
My current favourite word is: PIE!
Good ol' pie, it's been a while.
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can anyone help me please ??
Cheers
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Where is this code? You didn't provide it in your original post. If you have already managed to reverse the string and display it, you must have the reversed string in a variable to be returned from your method. The absence of this code suggests that you haven't written it at all and want someone else to do it for you. This isn't how the site works.
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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OMG...
ok then, i created a char array;
char[] myArray = new char[m]; //m is the length of array
read all the data into the array using;
for (int i =0; i<m; i++)
{
console.writeline..........="" bla="" bla
myarray[i]="Convert.ToChar(Console.Readline());
}
//" display="" in="" reverse
while="" (length="" !="-1)" length="" is="" declared="" elsewhere="" and="" holds="" the="" no.of="" chars
{
console.write(myarray[length];
length--;
}
now="" what="" i="" want="" to="" know="" a="" string="" passed="" into="" method="" resulting="" reversed="" returned?=""
ps="" have="" declaration="" at="" beginning="" of="" this="" thread.
=""
<div="" class="ForumSig">Cheers
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As just stated, if its not homework and you have working code then post it and someone here will explain the use of the return keyword for you.
I still call this out as homework.
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Of course this is homework, no company is going to pay for string reversals.
Maybe class gnirts could help, but sadly it has been postponed till the next
major upgrade of the .NET Framework. 
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets
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hmmmm... does that sound like a homework question?
you could use a stack to do this:
public void Main()
{
string foo = "i will do my homework on my own";
string blah = reverseString(foo);
Console.WriteLine(foo);
Console.WriteLine(blah);
}
public void reverseString(string Text)
{
System.Collections.Stack st = new Stack();
foreach (char c in Text)
{
st.Push(c);
}
ArrayList l = new ArrayList();
while (st.Count > 0)
{
l.Add(st.Pop());
}
char[] s = l.ToArray(typeof(char)) as char[];
string RetVal = new string(s);
return RetVal;
}
but if you use one of the other 999999999 possibilities to do it it'll be more efficient
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ok this is my method, the loop is not functioning, but i cant see y???
public string Reverse(string WhatToReverse)
{
int lengthOfArray = WhatToReverse.Length;
//char array
char[] myArray = new char[lengthOfArray];
for (int i = lengthOfArray; i < 0; i--)
{
myArray[i] = WhatToReverse[i];
Console.Write(myArray[i]);
}
return ;//still to complete, but the loop dont work
}
Cheers
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hustler2005 wrote: for (int i = lengthOfArray; i < 0; i--)
I is not less than 0 at the start.
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I prefer the following...
public void Main()
{
string str = "I will do my homework on my own";
IntPtr strPtr = Marshal.StringToHGlobalUni(str);
IntPtr resPtr = ReverseString(strPtr);
string res = Marshal.PtrToStringUni(result);
Marshal.FreeHGlobal(strPtr);
Marshal.FreeHGlobal(resPtr);
Console.WriteLine(str);
Console.WriteLine(res);
}
public IntPtr ReverseString(IntPtr strPtr)
{
string str = Marshal.PtrToStringUni(strPtr);
char[] strAsCharArray = new char[str.Length];
for (int i = 0; i < str.Length; ++i)
{
strAsCharArray[i] = str[0];
str = str.Substring(1);
}
StringBuilder sb = new StringBuilder(strAsCharArray.Length);
string res = string.Empty;
for (int i = 0; i < str.Length; i += 2)
{
string next = string.Empty;
for (int j = 1; j >= 0; --j)
{
if (i + j == str.Length)
continue;
char c = strAsCharArray[i + j];
next.Insert(0, c.ToString());
res.Insert(1 - j, c.ToString());
}
sb.Append(next);
}
str = sb.ToString();
IntPtr rval = Marshal.StringToHGlobalUni(res);
return rval;
}
This is O(n), which is as fast as this operation can be done given how strings are implemented in the system (with a double-linked-list, it can be O(1)). Hope this helps.
Jeff
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Since you already optimized the code, more in particular by unrolling the for loop,
it is actually more like O(n/2) which is quite good.
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets
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Thanks all sorted, this is what i used.......
public string Reverse(string WhatToReverse)
{
string str2 = string.Empty;
StringBuilder sb = new StringBuilder();
//char array
char[] myArray = WhatToReverse.ToCharArray();
for(int i = WhatToReverse.Length-1; i >=0; i--)
{
sb.Append(myArray[i].ToString());
}
str2 = sb.ToString();
return str2;
}
Cheers
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Good work! Post something like this and ask how to make it better, and we will honestly try to help (instead of the crappy roundabout ways we proposed to solve the problem earlier). The way I would implement this problem is as follows...
public string ReverseString(string str) {
StringBuilder result = new StringBuilder();
for (int i = str.Length - 1; i >= 0; --i)
result.Append(str[i]);
return result.ToString();
}
Like I said, show that you have put even a little effort into trying to find the answer by yourself, and we will try to give you the help you need to get it right, but don't expect us to give you the answer from scratch.
Jeff
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Just one adjustment; specify the capacity when you create the StringBuilder:
StringBuilder result = new StringBuilder(str.Length);
This will allocate a string with the exact right size. This has two advantages:
1. The StringBuilder never has to increase the capacity (which is done by allocating a new string with double the size, and copy the data from the previous string to it).
2. The string returned by the ToString method doesn't have any extra unused characters beyond the actual string. If you don't specify the length, the string may use up to twice as much memory as it needs to.
Experience is the sum of all the mistakes you have done.
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Wow... I can't beleive I missed that! 
Jeff
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Have you considered using Array.Reverse method?
string original = "original";
char[] reverseString = original.ToCharArray();
Array.Reverse(reverseString);
original = string.Empty;
for (int i = 0; i < reverseString.Length; i++)
original += reverseString[i];
I will use Google before asking dumb questions
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summing up to new string(Array.Reverse(original.ToCharArray())
or even better a sequence of original.ToCharArray(), Array.Reverse() and new string(char[])
-- modified at 15:58 Thursday 22nd November, 2007
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets
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No, you can't do like that. The Array.Reverse method doesn't return the reversed array, it reverses the array in place.
Experience is the sum of all the mistakes you have done.
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You're right of course. So I'd better turn it into a small method...
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use PRE tags to preserve formatting when showing multi-line code snippets
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Of course, as a quick and dirty hack you could always use a recursive method. I'm not saying you should, but you could. I've seen this done in so many homework assignments and coursework samples.
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The recursive method is pretty neat, actually. Who can resist a one-liner? 
Not very efficient, though.
public string Reverse(string value) { return value.Length > 1 ? Reverse(value.Substring(1)) + value.Substring(0, 1) : value; }
Experience is the sum of all the mistakes you have done.
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There you go then. The last step is to turn this into a delegate and you're laughing.
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Well, delegates can be used in many ways...
public string Reverse(string value) {
string result = string.Empty;
new List<char>(value.ToCharArray()).ForEach(delegate(char c) { result = c.ToString() + result; });
return result;
}
Experience is the sum of all the mistakes you have done.
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