Appending a string

[Paul Roberts]

Hiya

I have a string with about 300+ characters, how can i insert a line break or
another character every 50 characters for the whole string?

Paul Roberts

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

Basically, you cannot, String is an inmutable class.
What you can do is split the string in pieces, append the piece to a
StringBuilder, append Environment.New Line and repite the process.

I will let the coding to you, it's the fun part :)

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Paul Roberts" <Pa**********@c ompserve.com> wrote in message
news:dn******** ***********@new s.demon.co.uk.. .

Hiya

I have a string with about 300+ characters, how can i insert a line break
or another character every 50 characters for the whole string?

Paul Roberts

[Steve]

string x = "your long string";

for (int i = 50; i < x.Length; i += 50)
x = x.Insert(i, System.Enviornm ent.NewLine);

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

"Steve" <st**********@t icketmaster.com > wrote in message
news:11******** **************@ z14g2000cwz.goo glegroups.com.. .

string x = "your long string";

for (int i = 50; i < x.Length; i += 50)
x = x.Insert(i, System.Enviornm ent.NewLine);

It's better to use StringBuilder, with the above code you are generating a
lot of temp strings that consume resources.
cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

[Peter Rilling]

This is not very efficient since a new String object is created in each
loop.

"Steve" <st**********@t icketmaster.com > wrote in message
news:11******** **************@ z14g2000cwz.goo glegroups.com.. .

string x = "your long string";

for (int i = 50; i < x.Length; i += 50)
x = x.Insert(i, System.Enviornm ent.NewLine);

[Peter Rilling]

Rather than splitting the string, he could just initialize a new
StringBuilder with that string and use StringBuilder.I nsert to add the
characters. I think this will push the string.

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:e$******** ******@tk2msftn gp13.phx.gbl...

Hi,

Basically, you cannot, String is an inmutable class.
What you can do is split the string in pieces, append the piece to a
StringBuilder, append Environment.New Line and repite the process.

I will let the coding to you, it's the fun part :)

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Paul Roberts" <Pa**********@c ompserve.com> wrote in message
news:dn******** ***********@new s.demon.co.uk.. .

Hiya

I have a string with about 300+ characters, how can i insert a line break
or another character every 50 characters for the whole string?

Paul Roberts

[Bruce Wood]

If the string is, in fact, very long (thousands of characters) this
will result in a lot of unnecessary copying.

You're better off breaking up the string first, then gluing it back
together with newlines in between using StringBuilder.

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,
"Peter Rilling" <pe***@nospam.r illing.net> wrote in message
news:ex******** ********@TK2MSF TNGP14.phx.gbl. ..

Rather than splitting the string, he could just initialize a new
StringBuilder with that string and use StringBuilder.I nsert to add the
characters. I think this will push the string.

I think the same but I have no idea if that can be more efficient that
using Append , note that there is a version of Append that receive a string
and two integers and append that substring:
Append( string, start_index, end_index )

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

[Paul Roberts]

Can someone give me a head start? i'm having problems with it, and dont know
where to start.

"Ignacio Machin ( .NET/ C# MVP )" <ignacio.mach in AT dot.state.fl.us > wrote
in message news:e$******** ******@tk2msftn gp13.phx.gbl...

Hi,

Basically, you cannot, String is an inmutable class.
What you can do is split the string in pieces, append the piece to a
StringBuilder, append Environment.New Line and repite the process.

I will let the coding to you, it's the fun part :)

cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Paul Roberts" <Pa**********@c ompserve.com> wrote in message
news:dn******** ***********@new s.demon.co.uk.. .

Hiya

I have a string with about 300+ characters, how can i insert a line break
or another character every 50 characters for the whole string?

Paul Roberts

[Bruce Wood]

Here are some hints.

Look at the documentation for the StringBuilder class. Notice that you
can create an empty StringBuilder and append things to it, then convert
the finished product to a string using the ToString() method of your
StringBuilder object.

If you really want every exactly 50 characters, just check into the
Substring method of String. If you need to do a more sophisticated
determination of where to break the string, write a method that takes a
string and an index and returns the length of the substring to break
off. For example, if you wanted to break the string at a blank space,
but at most 50 characters, a method like this might be useful:

private static int LineLength(stri ng line, int startIndex)
{
int endIndex = startIndex + 50;
if (endIndex >= line.Length)
{
endIndex = line.Length - 1;
}
while (endIndex > startIndex && !Char.IsWhiteSp ace(line[endIndex]))
{
endIndex--;
}
if (endIndex <= startIndex)
{
// return 50 or the remainder of the string, whichever is less
return Math.Min(50, line.Length - startIndex);
}
else
{
return endIndex - startIndex;
}
}

The part where you break up the string and reassemble it with newlines
would look like this:

int startIndex = 0;
StringBuilder sb = new StringBuilder() ;
while (startIndex < line.Length)
{
if (sb.Length > 0)
{
... append a newline to the StringBuilder ...
}
... append a chunk of the string "line" to the StringBuilder
... update "startIndex " to be the next place in the string "line"
to start
}
.... convert the StringBuilder to a string

and you're done!