Replacing a substring at a specific position

Hi all, need some help.

I want to replace the second character in a string, regardless of what character that is.

If I try the replace the second character with the (substring 1, 1) all instances of that character gets replaced.
I just want to replace the one sitting at position 2 in the string.

Ex Good -> Gxod, not Gxxd

Thanks in advance

Patrik

paarfal,

One option is to use the classic BASIC MID statement:

Dim myString As String = "abcde"

Mid(myString, 2, 1) = "x"

MsgBox(myString)

(Of course, now the .Net purists will respond that you should not use the MID statement.)

Kerry Moorman

In VB, you can use the Mid statement:

Mid(theString, 2, 1) = "x"

There's no equivalent in C#. You could add a reference to the Microsoft.VisualBasic namespace and call the Mid statement from C#, or you could convert the string to an array of characters, update the desired character, then create a new string from the char array.

In VB, you could have (add semi-colon for C#)
myString = myString.Remove(1, 1).Insert(1, "x")

Of course, not quite as direct as the Mid statement.

in C# you can use in this way
TextBox2.Text =TextBox1.Text.Replace(TextBox1.Text.Substring(1,1),"p");

here p is the newly replaced char.

Raj: I'm pretty sure that will replace all occurrences of the second character with the letter 'p'. So, "good" would become "gppd".

Hi all,

Thaks for your suggestions. I'll try work it out based on them.

Regards,

Patrik

I think the best in C# would be:
TextBox2.Text =TextBox1.Text.Remove(1,1).Insert(1,"p");
cheers

Why couldn't you just use ...
newstring = LEFT(oldstring, 1) & newcharacter & MID(oldstring, 3)

That would work, but it's less efficient than Mid(theString, 2, 1) = "x" due to its use of concatenation.

Absolutely, but it is simpler to understand for new programmers. And the performance hit is only noticable if the number of iterations on it are extremely large.

OK, how about this:

' Replace second character of theString with 'x'
Mid(theString, 2, 1) = "x"

That's efficient and easy for new programmers to understand (and it doesn't teach them bad habits ;-).

Works for me! Personally I have always used MID() = X in the manner you describe. Although I wouldn't call the concatenation a "bad habit" ... just not the most efficient one.

A bit of filthy wat to do it, but it works.

string editString = "Good";

StringBuilder sb = new StringBuilder(editString);
sb.Remove(1, 1);
sb.Insert(1, "x");

editString = sb.ToString();