Question

I have the following string in C#.

"aaa,bbbb.ccc|dddd:eee"

I then split it with new char[] {',','.','|',':'}. How would I rejoin this string in the same order as before with the same characters? So the list would end up the exact same as it was before.

EXAMPLE

string s = "aaa,bbbb.ccc|dddd:eee";
string[] s2 = s.Split(new char[] {',','.','|',':'});
// now s2 = {"aaa", "bbbb", "ccc", "dddd", "eee"}
// lets assume I done some operation, and
// now s2 = {"xxx", "yyy", "zzz", "1111", "222"}

s = s2.MagicJoin(~~~~~~);  // I need this

// now s = "xxx,yyy.zzz|1111:222";

EDIT

the char[] in above sample just sample, not in same order or even will not all appear in same time in real world.

EDIT

Just a thought, how about use Regex.split, then first split by char[] get a string[], then use not the char[] to split get another string[], later just put them back. Maybe work but I do not know how to code it.

Answer 1

It might be easier to do this with the Regex class:

input = Regex.Replace(input, @"[^,.|:]+", DoSomething);

Where DoSomething is a method or lambda that transforms the item in question, e.g.:

string DoSomething(Match m)
{
    return m.Value.ToUpper();
}

For this example the output string for “aaa,bbbb.ccc|dddd:eee” would be “AAA,BBBB.CCC|DDDD:EEE”.

If you use a lambda you can very easily keep state around, like this:

int i = 0;
Console.WriteLine(Regex.Replace("aaa,bbbb.ccc|dddd:eee", @"[^,.|:]+",
    _ => (++i).ToString()));

Outputs:

1,2.3|4:5

It just depends on what kind of transformation you’re doing to the items.