Develop Reference

c# Change the format of a string

Edit:
Because of your responses I think I've asked the question wrong.
It's not that my solution doesn't work or isn't very clean. I'm interested if there is a general way, how you can foramt a string. Like you can do it with a int or other data types.
So I couldn't find one. But I hope there is one.
So that's the question I wanted to ask:
Does C# provides a way to format strings, like it does for a int or other data types?
I'm looking for something like this:
myString.Format(myFormat);
or:
myFormattedString = String.Format(myString, myFormat);
And if the answer is no, it's also ok. I just want to know it. (And maybe someone else as well)
Original question:
What's the best way to change the format of a string?
So I have a string that looks like this:
"123456789012345678"
And now I want that:
"12.34.567890.12345678"
I'm using this, but I don't find it very clean:
private string FormatString(string myString)
{
return myString.Insert(2, ".").Insert(5, ".").Insert(12, ".");
}
Things I've tried:
// Too long.
private string FormatString(string myString)
{
return myString.Substring(0, 2)
+ "."
+ myString.Substring(2, 2)
+ "."
+ myString.Substring(4, 6)
+ "."
+ myString.Substring(10, 8);
}
// Convertion from string -> long -> string.
private string FormatString(string myString)
{
return String.Format("{0:##'.'##'.'######'.'########}", long.Parse(myString));
}
I'm looking for something like that:
private string FormatString(string myString)
{
return String.Format("{0:##'.'##'.'######'.'########}", myString);
}

I don't see anything wrong with your code, but if you want a better matching system, you might want to consider regular expressions:
(\d{2})(\d{2})(\d{6})(\d{8})
And replace it with:
$1\.$2\.$3\.$4
(In action)
But my two cents: keep it like it is.

Well...when the framework does not provide what you want, you can always do it yourself.
I've made this method as a experiment. It can surely be optimized and is not fully tested, but it can give you a view of what you could do:
private string FormatString(string myString,string format)
{
const char number = '#';
const char character = '%';
StringBuilder sb = new StringBuilder();
if (format.Length < myString.Length) throw new Exception("Invalid format string");
int i = 0;
foreach (char c in format)
{
switch (c)
{
case number:
if (char.IsDigit(myString[i]))
{
sb.Append(myString[i]);
i++;
}
else
{
throw new Exception("Format string doesn't match input string");
}
break;
case character:
if (!char.IsDigit(myString[i]))
{
sb.Append(myString[i]);
i++;
}
else
{
throw new Exception("Format string doesn't match input string");
}
break;
default:
sb.Append(c);
break;
}
}
return sb.ToString();
}
This method expects the format string to have either a # to denote digit, a % to denote a character, or any other character that would be copied literally to the formatted string.
Usage:
string test = FormatString("123456789012345678", "##.##.######.########");
//outputs 12.34.567890.12345678
string test = FormatString("12345F789012345678", "##.##.#%####.########");
//outputs 12.34.5F7890.12345678

If your string will always be a number then you can do it like this:
string stringData = "123456789012345678";
string dataInFormat = Convert.ToInt64(stringData).ToString(#"##\.##\.######\.########");
First convert string to long and then implement the format on that. In your case it would be like this:
private string FormatString(string myString)
{
return Convert.ToInt64(myString).ToString(#"##\.##\.######\.########");
}

Remove parts of string

I have the following string
string a = #"\\server\MainDirectory\SubDirectoryA\SubdirectoryB\SubdirectoryC\Test.jpg";
I'm trying to remove part of the string so in the end I want to be left with
string a = #"\\server\MainDirectory\SubDirectoryA\SubdirectoryB";
So currently I'm doing
string b = a.Remove(a.LastIndexOf('\\'));
string c = b.Remove(b.LastIndexOf('\\'));
Console.WriteLine(c);
which gives me the correct result. I was wondering if there is a better way of doing this? because I'm having to do this in a fair few places.
Note: the SubdirectoryC length will be unknown. As it is made of the numbers/letters a user inputs

There is Path.GetDirectoryName
string a = #"\\server\MainDirectory\SubDirectoryA\SubdirectoryB\SubdirectoryC\Test.jpg";
string b = Path.GetDirectoryName(Path.GetDirectoryName(a));
As explained in MSDN it works also if you pass a directory
....passing the returned path back into the GetDirectoryName method will
result in the truncation of one folder level per subsequent call on
the result string
Of course this is safe if you have at least two directories level

Heyho,
if you just want to get rid of the last part.
You can use :
var parentDirectory = Directory.GetParent(Path.GetDirectoryName(path));
https://msdn.microsoft.com/de-de/library/system.io.directory.getparent(v=vs.110).aspx

An alternative answer using Linq:
var b = string.Join("\\", a.Split(new string[] { "\\" }, StringSplitOptions.None)
.Reverse().Skip(2).Reverse());

Some alternatives
string a = #"\\server\MainDirectory\SubDirectoryA\SubdirectoryB\SubdirectoryC\Test.jpg";
var b = Path.GetFullPath(a + #"\..\..");
var c = a.Remove(a.LastIndexOf('\\', a.LastIndexOf('\\') - 1));
but I do find this kind of string extensions generally usefull:
static string beforeLast(this string str, string delimiter)
{
int i = str.LastIndexOf(delimiter);
if (i < 0) return str;
return str.Remove(i);
}

For such repeated tasks, a good solution is often to write an extension method, e.g.
public static class Extensions
{
public static string ChopPath(this string path)
{
// chopping code here
}
}
Which you then can use anywhere you need it:
var chopped = a.ChopPath();

Extract multiple values from string using C#

I'am creating my own forum. I've got problem with quoting messages. I know how to add quoting message into text box, but i cannot figure out how to extract values from string after post. In text box i've got something like this:
[quote IdPost=8] Some quoting text [/quote]
[quote IdPost=15] Second quoting text [/quote]
Could You tell what is the easiest way to extract all "IdPost" numbers from string after posting form ?.

by using a regex
#"\[quote IdPost=(\d+)\]"
something like
Regex reg = new Regex(#"\[quote IdPost=(\d+)\]");
foreach (Match match in reg.Matches(text))
{
...
}

var originalstring = "[quote IdPost=8] Some quoting text [/quote]";
//"[quote IdPost=" and "8] Some quoting text [/quote]"
var splits = originalstring.Split('=');
if(splits.Count() == 2)
{
//"8" and "] Some quoting text [/quote]"
var splits2 = splits[1].Split(']');
int id;
if(int.TryParse(splits2[0], out id))
{
return id;
}
}

I do not know exactly what is your string, but here is a regex-free solution with Substring :
using System;
public class Program
{
public static void Main()
{
string source = "[quote IdPost=8] Some quoting text [/quote]";
Console.WriteLine(ExtractNum(source, "=", "]"));
Console.WriteLine(ExtractNum2(source, "[quote IdPost="));
}
public static string ExtractNum(string source, string start, string end)
{
int index = source.IndexOf(start) + start.Length;
return source.Substring(index, source.IndexOf(end) - index);
}
// just another solution for fun
public static string ExtractNum2(string source, string junk)
{
source = source.Substring(junk.Length, source.Length - junk.Length); // erase start
return source.Remove(source.IndexOf(']')); // erase end
}
}
Demo on DotNetFiddle

C# 2.0 function which will return the formatted string

I am using C# 2.0 and I have got below type of strings:
string id = "tcm:481-191820"; or "tcm:481-191820-32"; or "tcm:481-191820-8"; or "tcm:481-191820-128";
The last part of string doesn't matter i.e. (-32,-8,-128), whatever the string is it will render below result.
Now, I need to write one function which will take above string as input. something like below and will output as "tcm:0-481-1"
public static string GetPublicationID(string id)
{
//this function will return as below output
return "tcm:0-481-1"
}
Please suggest!!

If final "-1" is static you could use:
public static string GetPublicationID(string id)
{
int a = 1 + id.IndexOf(':');
string first = id.Substring(0, a);
string second = id.Substring(a, id.IndexOf('-') - a);
return String.Format("{0}0-{1}-1", first, second);
}
or if "-1" is first part of next token, try this
public static string GetPublicationID(string id)
{
int a = 1 + id.IndexOf(':');
string first = id.Substring(0, a);
string second = id.Substring(a, id.IndexOf('-') - a + 2);
return String.Format("{0}0-{1}", first, second);
}
This syntax works even for different length patterns, assuming that your string is
first_part:second_part-anything_else

All you need is:
string.Format("{0}0-{1}", id.Substring(0,4), id.Substring(4,5));
This just uses substring to get the first four characters and then the next five and put them into the format with the 0- in there.
This does assume that your format is a fixed number of characters in each position (which it is in your example). If the string might be abcd:4812... then you will have to modify it slightly to pick up the right length of strings. See Marco's answer for that technique. I'd advise using his if you need the variable length and mine if the lengths stay the same.
Also as an additional note your original function of returning a static string does work for all of those examples you provided. I have assumed there are other numbers visible but if it is only the suffix that changes then you could happily use a static string (at which point declaring a constant or something rather than using a method would probably work better).

Obligatory Regular Expression Answer:
using System.Text.RegularExpressions;
public static string GetPublicationID(string id)
{
Match m = RegEx.Match(#"tcm:([\d]+-[\d]{1})", id);
if(m.Success)
return string.Format("tcm:0-{0}", m.Groups[1].Captures[0].Value.ToString());
else
return string.Empty;
}

Regex regxMatch = new Regex("(?<prefix>tcm:)(?<id>\\d+-\\d)(?<suffix>.)*",RegexOptions.Singleline|RegexOptions.Compiled);
string regxReplace = "${prefix}0-${id}";
string GetPublicationID(string input) {
return regxMatch.Replace(input, regxReplace);
}
string test = "tcm:481-191820-128";
stirng result = GetPublicationID(test);
//result: tcm:0-481-1

What should I name this Extension method?

I have written an extension method for string manipulation. I'm confused what should I name it - since this will become part of the base library front-end developers in the team will use. Here's the profile of the class member.
Info: Utility Extension method for String types. Overloads of this method may do the same thing characters other than space [with what supplied in argument]
Purpose: Trims down all intermediate or in-between spaces to single space.
Ex:
string Input = "Hello Token1 Token2 Token3 World! ";
string Output = Input.TrimSpacesInBetween();
//Output will be: "Hello Token1 Token2 Token3 World!"
I have read [in fact I'm reading] the Framework Design guidelines but this seems to be bothering me.
Some options I think..
TrimIntermediate();
TrimInbetween();
Here's the code on Request:
It's recursive..
public static class StringExtensions
{
public static string Collapse(this string str)
{
return str.Collapse(' ');
}
public static string Collapse(this string str, char delimeter)
{
char[] delimeterts = new char[1];
delimeterts[0] = delimeter;
str = str.Trim(delimeterts);
int indexOfFirstDelimeter = str.IndexOf(delimeter);
int indexTracker = indexOfFirstDelimeter + 1;
while (str[indexTracker] == delimeter)
indexTracker++;
str = str.Remove(indexOfFirstDelimeter + 1, indexTracker - indexOfFirstDelimeter - 1);
string prevStr = str.Substring(0, indexOfFirstDelimeter + 1);
string nextPart = str.Substring(indexOfFirstDelimeter + 1);
if (indexOfFirstDelimeter != -1)
nextPart = str.Substring(indexOfFirstDelimeter + 1).Collapse(delimeter);
string retStr = prevStr + nextPart;
return retStr;
}
}

What about CollapseSpaces?

CollapseSpaces is good for just spaces, but to allow for the overloads you might want CollapseDelimiters or CollapseWhitespace if it's really just going to be for various whitespace characters.

Not really an answer, more a comment on your posted code...
You could make the method a lot shorter and more understandable by using a regular expression. (My guess is that it would probably perform better than the recursive string manipulations too, but you would need to benchmark to find out for sure.)
public static class StringExtensions
{
public static string Collapse(this string str)
{
return str.Collapse(' ');
}
public static string Collapse(this string str, char delimiter)
{
str = str.Trim(delimiter);
string delim = delimiter.ToString();
return Regex.Replace(str, Regex.Escape(delim) + "{2,}", delim);
}
}

In ruby I believe they call this squeeze

NormalizeWhitespace ?
This way is more clear that there will be a usable value left after processing.
As other have stated earlier, 'Collapse' sounds somewhat rigorous and might even mean that it can return an empty string.

Try this, it works for me and seems to be a lot less complicated than a recursive solution...
public static class StringExtensions
{
public static string NormalizeWhitespace(this string input, char delim)
{
return System.Text.RegularExpressions.Regex.Replace(input.Trim(delim), "["+delim+"]{2,}", delim.ToString());
}
}
It can be called as such:
Console.WriteLine(input.NormalizeWhitespace(' '));

CollapseExtraWhitespace

PaulaIsBrilliant of course!

How is makeCompact?