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How to do I cut off a certain part a String?

I have a big String in my program.
For Example:
String Newspaper = "...Blablabla... What do you like?...Blablabla... ";
Now I want to cut out the "What do you like?" an write it to a new String. But the problem is that the "Blablabla" is everytime something diffrent. Whit "cut out" I mean that you submit a start and a end word and all the things wrote between these lines should be in the new string. Because the sentence "What do you like?" changes sometimes except the start word "What" and the end word "like?"
Thanks for every responds

You can write the following method:
public static string CutOut(string s, string start, string end)
{
int startIndex = s.IndexOf(start);
if (startIndex == -1) {
return null;
}
int endIndex = s.IndexOf(end, startIndex);
if (endIndex == -1) {
return null;
}
return s.Substring(startIndex, endIndex - startIndex + end.Length);
}
It returns null if either the start or end pattern is not found. Only end patterns that follow the start pattern are searched for.
If you are working with C# 8+ and .NET Core 3.0+, you can also replace the last line with
return s[startIndex..(endIndex + end.Length)];
Test:
string input = "...Blablabla... What do you like?...Blablabla... ";
Console.WriteLine(CutOut(input, "What ", " like?"));
prints:
What do you like?
If you are happy with Regex, you can also write:
public static string CutOutRegex(string s, string start, string end)
{
Match match = Regex.Match(s, $#"\b{Regex.Escape(start)}.*{Regex.Escape(end)}");
if (match.Success) {
return match.Value;
}
return null;
}
The \b ensures that the start pattern is only found at the beginning of a word. You can drop it if you want. Also, if the end pattern occurs more than once, the result will include all of them unlike the first example with IndexOf which will only include the first one.

You have to do a substring, like the example below. See source for more information on substrings.
// A long string
string bio = "Mahesh Chand is a founder of C# Corner. Mahesh is also an
author, speaker, and software architect. Mahesh founded C# Corner in
2000.";
// Get first 12 characters substring from a string
string authorName = bio.Substring(0, 12);
Console.WriteLine(authorName);

In this case I would do it like this, cut the first part and then the second and concatenate with the fixed words using them as a parameter for cutting.
public string CutPhrase(string phrase)
{
var fst = "What";
var snd = "like?";
string[] cut1 = phrase.Split(new[] { fst }, StringSplitOptions.None);
string[] cut2 = cut1[1].Split(new[] { snd }, StringSplitOptions.None);
var rst = $"{fst} {cut2[0]} {snd}";
return rst;
}

remove text in between delimiters in a string - regex

I have been trying real hard understanding regular expression, Is there any way I can replace character(s) that is between two regex/ For example I have
string datax = "a4726e1e-babb-4898-a5d5-e29d2bc40028;POPULATE DATA AØ99c1d133-15f5-4ef5-bc59- d9ed673b70c6;POPULATE DATA BØ";
how to remove string between regex ";" and "Ø" ???
i try to use code like this :
string xresult = Regex.Replace(datax, #"(?<=;)(\w+?)(?=Ø)", "");
But not working.
please corrected and give me solutions...
thanks...
i want the result like this sir :
string datax = "a4726e1e-babb-4898-a5d5-e29d2bc40028;Ø99c1d133-15f5-4ef5-bc59-d9ed673b70c6;Ø";

I think you need to understand regex a little better and how the replace function works. with regex you're defining capture groups, and with the replace function you want to replace those groups.
how to remove string between regex ";" and "Ø" ???
Step 1: First find ";",then capture all characters up to and including "Ø".
That's (;.*?Ø)
( New Capture Group
; Match ";"
. Match Anything
* Zero or more times
? Be Lazy
Ø Match "Ø"
) End Capture
Step 2: Replace each group with ";Ø"
public static string Replace(string input, string pattern, string
replacement)
So you need to put back the ";Ø" you removed from the original capture.
static void Test2()
{
foreach (string item in SO2588078())
{
Console.WriteLine(item);
}
string input = "a4726e1e-babb-4898-a5d5-e29d2bc40028;POPULATE DATA AØ99c1d133-15f5-4ef5-bc59- d9ed673b70c6;POPULATE DATA BØ";
string regex = "(;.*?Ø)";
string output = Regex.Replace(input, regex, ";Ø");
if (output == string.Join(";Ø", SO2588078()) + ";Ø")
{
Console.WriteLine("TRUE");
}
}
An alternative would be to parse the string without regex. It's a simple format and this gives you more control over the process so you can see what's happening, why it's gone wrong and why it gives the results it does. Since you can step through it.
private static IEnumerable<string> SO2588078()
{
string datax = "a4726e1e-babb-4898-a5d5-e29d2bc40028;POPULATE DATA AØ99c1d133-15f5-4ef5-bc59- d9ed673b70c6;POPULATE DATA BØ";
string temp = datax;
while (!string.IsNullOrEmpty(temp))
{
int index1 = temp.IndexOf(';');
if (index1 > -1)
{
string guid = temp.Remove(index1);
yield return guid;
int index2 = temp.IndexOf('Ø');
if (index2 > -1)
{
temp = temp.Substring(index2 + 1);
}
else
{
temp = null;
}
}
else
{
temp = null;
}
}
}

Move part of string to another string

Maybe I don't have the right keywords but I can't seem to find how to do it.
Let's say I have these two string :
firstString = "I am a string";
secondString = "I am a long";
Is there a method that would allow me to move part of string 1 to string 2 ?
Move, not copy.
The final results would be :
firstString = "I am a"
secondString = "I am a long string"
The Problem
I have a string that contains a lot of characters. I want to send this string to SQLServer but the function that receives it can't hold more than 8000 char. So I need to send a request every 8000 characters.
Check if String1 is longer than 8000 Char
If it is, take the first 8000 Char and MOVE them into String2
Insert String2 into SQL
Repeat
If it's lenght is smaller than 8000 Char, send String 1 to SQL

Strings are immutable so what you are really doing is reassigning part of firstString to itself and assigning the other part concatenated to the end of secondString. There is no built in method to achieve this, but the code is pretty simple
secondString += firstString.Substring(6);
firstString = firstString.Substring(0,6);

Is there a method that would allow me to move part of string 1 to string 2 ? Move, not copy.
Since .NET strings are immutable, they cannot support methods with "move" semantic. Every modification of a string requires creation of a new object, entailing copying.
EDIT (in response to the edit of the question) It looks like your problem has to do with splitting the string at 8K characters, not necessarily moving parts of the string. In this case, you could use this simple code to pass parts of the string to SQL:
string string1 = GetReallyLongString();
const int sqlMax = 8000;
while (true) {
if (string1.Length > sqlMax) {
SendToSql(string1.Substring(0, sqlMax));
string1 = string1.Substring(sqlMax);
} else {
SendToSql(string1);
break;
}
}
Here is a quick demo on ideone.

As strings are immutable, you can't change them. You create new strings with parts from the original strings:
firstString = "I am a string";
secondString = "I am a long";
// concatenate second string with part from first string
secondSring = secondString + firstString.Substring(6);
// create a new string from part of the first string
firstString = firstString.Substring(0, 6);

Many ways to do that:
var partofstring = firstString.Substring(10, 14);
firstString = firstString.Replace(partofstring, "");
secondString += partofstring;

Inspired by dasblinkenlight's solution, but using yield to make a static method, and using as few substrings as possible to reduce memory usage.
using System;
using System.Collections.Generic;
public class Test
{
public static void Main()
{
string string1 = "quick brown fox jumps over the lazy dog";
foreach (var strSection in string1.SplitInto(8))
Console.WriteLine("'{0}'", strSection);
}
}
public static class MyExtensions
{
public static IEnumerable<string> SplitInto(this string value, int size)
{
for (int i = 0; i < value.Length; i += size)
{
if (i + size <= value.Length)
yield return value.Substring(i, size);
else
yield return value.Substring(i);
}
}
}
See it run at Ideone.

How to split a string with '#' in C#

I tried to split a string wich contains these character #
domicilioSeparado = domicilio.Split(#"#".ToCharArray());
but every time the array contains just one member. I've tried a lot of combinations but anything seems to work, I also tried to replace the string with a blank space and it kinda works - the problem is that it remains a single string.
domicilio = domicilio.Replace(#"#", #" ");
How can I resolve this?
Complete code:
String[] domicilioSeparado;
String domicilio = dbRow["DOMICILIO"].ToString();
domicilioSeparado = domicilio.Split(#"#".ToCharArray());
if (Regex.IsMatch(domicilioSeparado.Last(), #"\d"))
{
String domicilioSinNum = "";
domicilioSinNum = domicilioSeparado[0];
custTable.Rows.Add(counter, dbRow["CUENTA"], nombre,
paterno, materno, domicilioSinNum, domicilioSeparado.Last(), tipoEntidad);
}

If you just want to split a string on a delimiter, in this instance '#', then you can use this:
domicilioSeparado = domicilio.Split("#");
That should give you what you want. Your second attempt simply replaces all the characters '#' in the string with ' ', which doesn't seem to be what you want. Can we see the string you're trying to split? That might help explain why it's not working.
EDIT:
Ok, here's how I think your code should look, give this a shot and let me know how it goes.
List<string> domicilioSeparado = new List<string>();
String domicilio = dbRow["DOMICILIO"].ToString();
domicilioSeparado = domicilio.Split("#");
if (Regex.IsMatch(domicilioSeparado.Last(), #"\d"))
{
String domicilioSinNum = "";
domicilioSinNum = domicilioSeparado[0];
custTable.Rows.Add(counter, dbRow["CUENTA"], nombre,
paterno, materno, domicilioSinNum, domicilioSeparado.Last(), tipoEntidad);
}

Try this:
string[] domicilioSeparado;
domicilioSeparado = domicilio.Split('#');
Some notes:
1 - It is ('#'), instead of ("#"); 2 - Replace does not split a string, it only replace that part, keeping as a single string.
In case you want an example that includes the printing of the whole array:
string domicilio = "abc#def#ghi";
string[] domicilioSeparado;
domicilioSeparado = domicilio.Split('#');
for (int i = 0; i < domicilioSeparado.Length; i++)
{
MessageBox.Show(domicilioSeparado[i]);
}
It will open a Message Box for each element within domicilioSeparado.

replace a character in a string in c# based on position with a string

I want to replace a charecter in a string with a string in c#.
I have tried the following,
Here in the following program, i want replace set of charecters between charecters ':' and first occurance of '-' with some others charecters.
I could able to extract the set of charecters between ':' and first occurance of '-'.
Can any one say how to insert these back in the source string.
string source= "tcm:7-426-8";
string target= "tcm:10-15-2";
int fistunderscore = target.IndexOf("-");
string temp = target.Substring(4, fistunderscore-4);
Response.Write("<BR>"+"temp1:" + temp + "<BR>");
Examples:
source: "tcm:7-426-8" or "tcm:100-426-8" or "tcm:10-426-8"
Target: "tcm:10-15-2" or "tcm:5-15-2" or "tcm:100-15-2"
output: "tcm:10-426-8" or "tcm:5-426-8" or "tcm:100-426-8"
In a nutshell, I want to replace the set of charectes between ':' and '-'(firstoccurance) and the charecters extracetd from the same sort of string.
Can any help how it can be done.
Thank you.

If you want to replace the first ":Number-" from the source with the content from target, you can use the following regex.
var pattern1 = New Regex(":\d{1,3}-{1}");
if(pattern1.IsMatch(source) && pattern1.IsMatch(target))
{
var source = "tcm:7-426-8";
var target = "tcm:10-15-2";
var res = pattern1.Replace(source, pattern1.Match(target).Value);
// "tcm:10-426-8"
}
Edit: To not have your string replaced with something empty, add an if-clause before the actualy replacing.

Try a regex solution - first this method, takes the source and target strings, and performs a regex replace on the first, targetting the first numbers after the 'tcm', which must be anchored to the start of the string. In the MatchEvaluator it executes the same regex again, but on the target string.
static Regex rx = new Regex("(?<=^tcm:)[0-9]+", RegexOptions.Compiled);
public string ReplaceOneWith(string source, string target)
{
return rx.Replace(source, new MatchEvaluator((Match m) =>
{
var targetMatch = rx.Match(target);
if (targetMatch.Success)
return targetMatch.Value;
return m.Value; //don't replace if no match
}));
}
Note that no replacement is performed if the regex doesn't return a match on the target string.
Now run this test (probably need to copy the above into the test class):
[TestMethod]
public void SO9973554()
{
Assert.AreEqual("tcm:10-426-8", ReplaceOneWith("tcm:7-426-8", "tcm:10-15-2"));
Assert.AreEqual("tcm:5-426-8", ReplaceOneWith("tcm:100-426-8", "tcm:5-15-2"));
Assert.AreEqual("tcm:100-426-8", ReplaceOneWith("tcm:10-426-8", "tcm:100-15-2"));
}

I'm not clear on the logic used to decide which bit from which string is used, but still, you should use Split(), rather than mucking about with string offsets:
(note that the Remove(0,4) is there to remove the tcm: prefix)
string[] source = "tcm:90-2-10".Remove(0,4).Split('-');
string[] target = "tcm:42-23-17".Remove(0,4).Split('-');
Now you have the numbers from both source and target in easy-to-access arrays, so you can build the new string any way you want:
string output = string.Format("tcm:{0}-{1}-{2}", source[0], target[1], source[2]);

Heres without regex
string source = "tcm:7-426-8";
string target = "tcm:10-15-2";
int targetBeginning = target.IndexOf("-");
int sourceBeginning = source.IndexOf("-");
string temp = target.Substring(0, targetBeginning);//tcm:10
string result = temp + source.Substring(sourceBeginning, source.Length-sourceBeginning); //tcm:10 + -426-8