decrement a foreach

  • Thread starter Thread starter Elementary Penguin
  • Start date Start date
E

Elementary Penguin

is there a way to decrement a foreach loop?

for example

string s = "cat";

foreach(char c in s)
//some how it goes backward here
Console.WriteLine(c);

and so the result would be

t
a
c
 
Hi,

Why you think you go forwards?

You are sure you go forwards with
for i as integer = 0 to Cat.length-1
Cat(i)
next

Cor
 
Why not use a for loop?

string s = "cat";

for (int i = s.Length-1; i >= 0; i--)
Console.WriteLine(s.Substring(i,1));
 
Sorry,

I thought I was answering from the general newsgroup otherwise I would have
done it in C#, however Mick did that already

Cor
 
You could optionally resort the string in the reverse order and then run your
foreach loop as usual. eg.

class ReversedComparer:IComparer
{
public int Compare(object x,object y)
{
if((char)x < (char)y)
return 1;
else if((char)x > (char)y)
return -1;
else
return 0;
}
}


Array array = s.ToCharArray();
Array.Sort(array,new ReversedComparer());
//s = new String((char[])array);

foreach(char c in array)
{
Console.WriteLine(c);
}
 
Mick said:
Why not use a for loop?
Click to expand...

I like having access to the iterator in the body of the for code.

So, being able to use char r, and having it be indexxed, is a real benefit.

I guess the solution is to pass in a reversed string, but that seems really
inefficient.

I guess this is why the c people invented pointers...
 
couple of options:

1~ go backward:
for(int i=s.Length-1; i>=0; i--)
Console.WriteLine(s);

2~ use a Stack:
Stack stack = new Stack();
foreach(char c in s)
stack.Push(c);
while(stack.Count>0)
Console.WriteLine((char)stack.Pop());

F.O.R.
 
Elementary Penguin said:
I like having access to the iterator in the body of the for code.

So, being able to use char r, and having it be indexxed, is a real benefit.
Click to expand...

Just use the indexer of the string:

for (int i=s.Length-1; i >= 0; i--)
{
char r = s;
// ...
}

At that point you can do everything you could with a foreach, and more,
as you know the index (which you don't with foreach).
I guess the solution is to pass in a reversed string, but that seems really
inefficient.
Click to expand...

If you really wanted to use foreach and you're only interested in
strings, you could always your own enumerator which iterates through a
string's characters backwards.
 
Olorin,
2~ use a Stack:
Stack stack = new Stack();
foreach(char c in s)
stack.Push(c);
while(stack.Count>0)
Console.WriteLine((char)stack.Pop());
Click to expand...
Little bit crazy to use, however nice as sample.

:-)

Cor
 
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